US2018391A - Rotary compressor unit - Google Patents

Description

J. E. WHITFIELD ROTARY COMPRESSOR UNIT oct. 22, 1935.

Filed No', 18, 195:5 sheets-sheet 1 Oct. 22, 1935. J, E W|||TF|ELD 2,018,391

ROTARY COMPRESSOR UNIT I 4 Sheets-Sheet 2 ggem Filed Nov. 18. V1955 INVENTOR oct. 22, 1935. J. E, WHITFIELD 2,018,391

ROTARY QOMPRESSOR UNIT l. I @fd/mam@ Oct. 22, 1935. J, E WHITFIELD 2,018,591

ROTARY COMPRESSOR UNI T Filed Nov. 18, 1953 i 4 Sheets-Sheet 4 Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE 2,018,391 ROTARY COMPRESSOR Um'r Joseph E. Whitfield, Butler, Pa. Application November 18, 1933Serial No. 698,647 3 Claims. (Cl. 230-140) invention can be employed in other ways, as

hereinafter indicated.

One object of my invention is to provide a rO- tary compressor and motor of such form that there is a minimum loss of pressure between relatively moving parts, such as vanes or pistons, and their cooperating members, and wherein frictional resistance and wear is reduced to a minimum.

Another object of my invention is to provide an improved form of rotary compressor blade and`an improved manner of mounting the same.

Still another object of my invention is to provide an improved arrangement of rotary compressor ring or cage.

, A further object of my invention is to provide means for securing higher pressures by compressors of the rotary type.

Another object of my invention is to provide an improved mounting for a rotary compressor ring or cage.

lAnother object 'of my invention is to provide an improved means for cooling rotary engine compressors and the dike.

Another object of my invention is to provide means for supplying gaseous fuel from a compressor to a rotary motor, at constant pressure, notwithstanding changes in speed.

Apparatus embodying my invention is shown in the accompanying drawings wherein Figure 1 is a longitudinal sectional view through a compressor and motor unit, taken on the line I-I of Fig. 2; Fig. 2 is a view taken on the line II-H of Fig. 1; Fig. 3 is a view taken on the line III- III of Fig. 1;

' Fig. 4 is a view taken on the line IV-IV of Fig. 1; Fig. 5 is a view taken on the line V-V of Fig. 4; Fig. 6 is an enlarged sectional view ofone of the rotor blades; Fig. 7 is a side view thereof, partially in section; Fig. 8 is a sectional view through certain of the ports for circulationof the cooling fluid; Fig. 9 is a view taken on the line IX--IX of Fig. 8, and Fig. 10 is a sectional view taken on the line X-X of Fig.'4. l l

As-shown moreclearly in Fig. 1, I provide a. compressor casing I2 and a motor casing I3 which may be formed integrally, as shown on the drawings, or formed separately and secured together in any suitable manner. End plates I4 and I5 are provided for these casing members. The end plate I4 carries an anti-friction bearing I6 in which a compressor shaft I' I is journaled, the

other end of the shaft I1 having telescopicallykeyed or splined connection at I8 with a motor shaft I9. Theend plate I4 also carries an antifriction bearing 2| which supports one end of a slotted cage or drum 22, the cage having a cylin- 5 drical extension or hub 23 which is directly supported by the bearing. The other end of the cage has a cylindrical extension or hub 2li that is supported by an anti-friction bearing 25 which is mounted in an annular shoulder 26 of the coml0 pressor casing I2.

It will 4be seen that the cage 22 and the bearing 25, together with the shaft I'l and the parts carried thereby can be inserted and removed by taking off the end plate I4.

The shaft II is enlarged intermediate its ends to form a rotor 28 which is provided with radial slots for the reception of blades or vanes 29. The radial slots in the rotor 28 are shallow intermediate their ends as shown more clearly in Fig. 1, and the vanes 29 have their ends extended into the deeper portions of the slot. This arrangement gives extended radial sliding surfaces for the vanes 29, to reduce twisting or ,binding thereof under pressure, and still does not unduly weaken the rotor 28.

The rotor 28 is provided on its periphery with gear teeth 3D which extend clear across the face of the rotor along lines between the vanes 29. These teeth mesh with complementary-formed slots 3| vextending through the cage 22 radially, and thereby serve not only to rotate said cage, but function to displace the air or gas as hereinafter explained. The cage 22 is eccentric to the rotor 28, as shown more clearly in Fig. 3.

Each of the blades 29 carries a wiping shoe 32 which has segmental or arcuately-formed endportions 33 that lie in guide slots 34 formed in the end walls of the cage 22, as shown more clearly in Figs. 1 and 3. These guide slots 34 are concentricA with the cage 22, so that as the shaft I1 and its rotor 28 rotate, the vanes 29 will be held in contacting relation with the inner periphery of the cage 22, as shown in Fig. 3. The blades 29 are provided with arcuate lugs 35 which lie within the 45 semi-circular recesses 36 formed in the end portions of the shoes 32, so that the shoes will be held in assembled relation with the vanes and will have A rocking movement thereon.

The outermost faces of the shoes 32 have 50 a curvature corresponding to the curve of the compressor cage 22, so that there is a fairly wide contacting surface instead of a line contact between these members, whereby there is less danger of escape of fluid between the same when compression is taking lace. The shoes 32 have rocking movement on the vanes 29, so that they may maintain proper contact with the compressor cage 22 at all points throughout the circle, notwithstanding the eccentric relation of Y the cage relative to the rotor 28. As above explained, the compressor cage is independently supported in the bearings 2| and 25, so that it may have a running fit in the casing I2, without frictional power losses, and without excessive wear on the cage, such as would be the vcase if the cage were directly supported by the wall of the casing I2.

The rotor 28 will, of course, rotate more than one complete revolution for each revolution of the compressor cage 22, since it is in effect an external gear cooperating with such cage, which is an internal gear, and the number of teeth on the rotor are fewer than the number of slots in the cage 22. As shown on the drawings, the rotor 28 will make 8 revolutions to each '7 revolutions of the cage 22, though, of course, this could be varied to suit conditions. The shoes, therefore, make only one complete revolution relative to the cage to each 8 revolutions of rotor 28.

The amount of friction between the shoes 32 and the cage 22 is therefore much less than would be the case if the shoes contacted directly with the inner wall of the casing.

'I'he air and gas inlet for the compressor casing I2 is shown at 31. The gaseous medium will enter Vthe space 38 in the casing and pass through the slots 3| of the cage 22; said air will be trapped or .caught by the vanes at the point 40, and as the ring 22 and the rotor 28 continue to rotate in the direction of the arrow (Fig. 3), the entrapped volumes of gas will be gradually compressed as each 'vane 29 aproaches a discharge voutlet 42. Immediately preceding the actual discharge'at 42, through the slots 3|, the teeth 38 enter the slots, and by reason' of their close fit therewith, function as displacement members to still further compress the gas, thus producing much higher pressures at 42 than would otherwise be possible. Also, this insures discharge of practically all of the compressed gas at v42. Packing 43 is provided to prevent escape of gas beyond the outlet 42. The 'outlet 42 communicates with an annular reservoir 44, from which the compressed gas is directed to the motor as hereinafter explained. l

'I'he compressor ring 22 has widened unslotted areas 45 (Fig. 3) which are so positioned that they will be engaged by the shoes when passing the discharge outlet 42, whereby danger of leakage of "compressed gas ahead of and behind the discharge 42 is reduced.

In order to prevent excessive accumulation'of pressure in the reservoir 44, I provide a piston and cylinder 46fwhich is acted upon by pressure from the reservoir, so that when such pressure exceeds a predetermined degree, the piston will be operated to move the valve 41 towards closed position, thereby limiting admission of further air or gas for compression. Upon reduction of pressure in the reservoir, a spring ,48 will return the valve to open position.

Description of motor The motor shaft I9 is supported in bearings 56 and 5I. The bearing 50 is supported in a hublike extension or flange' 52 of the casing I3, while the bearing 5I is supported in a hub 53 carried by the end plate I5. The shaft I9 carries a rotor 55 which-is provided With a pair of vanes 56 and 51 that function as pistons as hereinafter explained. The rotor is provided with end plates or walls 58 which overlie the ends of the pistons 56 and 51, to form combustion spaces 59 between such pistons. I'he inner surface of the casing I3 forms the outer walls of these combustion spaces, and the periphery of the drum 55 forms the inner wall thereof.

A shaft 69 is journalled.I in the upper portion of the casing I3 in bearings 6I and 62 carried by 1 the said casing and the end plate I5, respec-y tvely.- A rotary abutment 64 is carried by said shaft and has a depression or slot 65 for receiving the pistons 56 and 51 successively. The

shaft `is driven from the shaft I9 by gear 15 wheels 66 and 61, the gear reduction being 2 to 1, so that the recess will be in position to receive each piston during movement of the same past the rotary abutment. A similar r0- tary abutment 68 is provided diametrically op- 2 posite 'to the abutment 64 and is driven in the same manner, and also functions in the same manner as the abutment 64. The end walls 58 of the rotor 55 have ports 10 immediately to the rear of the pistons 56 and 51, for the purpose 2 of admitting gas to the combustion spaces 59 between the rear sides of the pistons and th cooperating rotary abutments.

Compressed gas from the reservoir 44 is permitted to enter the ports 10, through ports 16 3 and 11 provided in plates 13 and 14' (Fig. 5). 'I'he plate 14 is xed in position by press fit with the casing I3 or otherwise, while the plate 13 is rotatably adjustable by means of a lever 15. so that the ports 16 in the plate 13 can be ad- 3 justably brought into registry with the ports 11 in the platey 14, to a desired degree, depending upon the quantity of fuel desired.

An important feature of the invention resides in the fact that the reservoir 44 is of much 40 16-11 are partly opened or fully opened, owing,

to the fact that there is sulcient capacity in the reservoir 44 to always supply compressed gas at substantially a full given pressure even when the motor is running withthe ports fully opened.

It will be obvious that since the fuel charges 65 are always under high pressure at theftime of firing, a maximum efficiency is obtainable. The engine will be as fully eiicient at part loads as at full loads.

Spark plugs 8 6 are provided for exploding the 69 charges of gas at properly timed intervals after the ports 10 have passed the ports 16, the spark being effected, of course, in time relation to movement of the shaft I9, in any suitable wellknown manner. ' I'he abutments 64 and 68 confine the explosions at the rear ends 4of the ring chambers. During the expansion of the fired charge, the pistons 56-51 move toward the exhaust ports 8|, through which the burnt gases are discharged, the dead gases of the previous charges being forced out through said ports.

It will be seen that there are 4 Aexplosions during each revolution of the rotor 55. The pistons 56 and 51 have merely clearance t with the re- 75 cesses 65 of the abutment rotors B4 and 88.

Teeth 18 on the rotary abutments 64 and 68Y Cooling system Cooling of the motor shaft and rotor 55 is effected by circulating water or other cooling fluid through the passages` formed internally thereof, thus cooling water will enter from a` tube 85; through a packing gland 86, within which are mounted perforated rings 81 and 88 and suitable packing material, the packing material being compressible through adjustment oi the members 86 and 89.

The shaft -l9 is provided with radial passages 90 through which water may flow from the perfil forated ring 81. The water is then conducted through the shaft by a tube 8| from whence it flows through passageways to the interior of the rotor 55 and against the end walls 58 thereof, the liquid then passing out through a passageway 92 to a discharge opening 93. The water is conducted to the interiors of the abutment rotors 64 and 68, except that the shafts thereof are of such length that the water may be supplied at 94, directly into the end of the shaft, and is discharged at 95 in a manner similar to the discharge at 93. The motor casing I3 is cooled by circulation of water between the double walls thereof in the usual manner.

The compressor structure can also be utilized as a general purpose pump, although if used with liquids, clearance would have to be provided between the teeth 30 and the slots 3|. Likewise, the motor structure'could be used otherwise than as an internal combustion engine, since it could be driven simply by steam or compressed air, for example.

I claim as my inventionz- 1. A rotary compressor comprising a casing having inlet and discharge openings, a compressor cage within the casing and having running t with the inner peripheral wall thereof through a portion of its circumference, a rotor eccentrisei 3 cally positioned in the cage and having engagement therewith when passing from the discharge opening to the inlet opening, radially-movable vanes carried by the rotor, meansfor maintaining the vanes in contact with the inner periphery of the cage, and a plurality of teeth carried by the rotor between each of said adjacent vanes and arranged to move into slots formed in the cage, when passing from the discharge to the inlet opening, the vanes being provided with shoes of greater width than the width of the teeth and the cage having widened unslotted portions with which the shoes engage when passing the said discharge opening.

2. A rotary compressor comprising a casing having inlet and discharge openings, a compressor cage within the casing and having running t with the inner peripheral wall thereof through a portion of its circumference, a `rctor eccentrically positioned in the cage and having engagement therewith when passing from the discharge opening to the inlet opening, radiallymovable vanes carried by the rotor, means for maintaining the vanes in contact with the inner periphery of \the cage, and teeth carried by the rotor, between vanes and arranged to move into slots -formed in the cage, when passing from the discharge to the inlet opening, the vanes being provided with shoes of greater width than the Width of the teeth and the cage having widened unslotted portions with which the shoes engage -when passing the said discharge opening.

3. A rotary compressor comprising a casing' having inlet and discharge openings, a compressor cage within the casing and having running fit with the inner peripheral wall thereof through a portion of its circumference, a rotor eccentrically positioned in the cage and having engagement therewith when passing from the discharge opening to the inlet opening, radially-movable vanes carried by the rotor, means for maintaining the vanes in contact with the inner periphery of the cage, teeth carried by the rotor, between vanes and arranged to move into slots formed in the cage, when passing from the discharge to tle inlet opening, the vanes being provided with -shoes of greater width than the width of the teeth and the cage having widened unslotted portions with which the shoes engage when passing the said discharge opening, and means for supporting said shoes for rocking movement on their longitudinal axes, relative to their respective vanes.

JOSEPH E. WHI'I'FIEID.

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