US2268929A - Compressor or the like - Google Patents

Description

Jan. 6, 1942-' E. DUPONT 2,268,929

' COMPRESSOR OR THE; LIKE Filed July 28, 1939 '4 Sheets-Sheet l FigJ Java/dob I 541/25 .DJPQ/Y'Ij Jan. 6, 1942. E. DUPONT 2,268,929

COMPRESSOR OR THE, LIKE Filed July 28, 1939 4 Sheets-Sheet 2 Fig.2

Jan. 6, 1942.

COMPRESSOR OR THE LIKE E. DUPONT Filed July 28, 1959 '4 Sheets-Sheet 3 Java/aim EM/ZE 20PM Jan. 6, 1942. E. DUPONT COMPRESSOR OR THE LIKE Filed July 28, 1959 4 Sheets-Sheet 4 Y taching a paddle or blade,

Patented Jan. 6, 1942 UNITED STATES. PATENT OFFICE oomans'sifffiz manna I Emile Dupont, Antibes, France Application July 28, 1939, Serial No. 287,166

In France February 3, 1939 3 Claims. (Cl. 230-131) An airplane flying at a high altitude, where the air pressure is low, must be supplied with air or carburated air through the medium of a compressor providing in the engine inlet pipe a pres sure comparable to'the atmospheric pressure on the ground.

The first object of the present invention is to reduce the power required by the compressor byincreasing the efliciency of the latter. V

The present invention also tends to decrease the heating of the carburated air. before its inlet into the engine cylinders. Then, it becomes possible to increase the compression ratio without any risk of creatingpre-ignition.

The invention also has for its object to reduce the angular speed of the compressor impellers, due to the increased efl'iciency.

The present invention also tends, further to the reduction of speed of the compressor wheels, to-simplif y or suppress the speed reduction mechanism interposed between the airplane engine and the compressor, and to reduce the quantity of lubricant used.

The invention will be understood from the following specification.

An impeller unit or turbo-compressor, in accordance with the invention, is represented, by way of example, in the enclosed drawings wherein:

Fig. 1 is a side elevation with one half shown in section of the form of apparatus with two fluid streams arranged in series.

metal, is attached to wheel 2, for instance, by means of screws 8 distributed around a circumference next to the hub of the shaft l. The disc 1 contacts wheel 2 on machined bearing surfaces 9 and I0 and further has-a circular groove ll, next to the icircumference of the attaching screws 8, and in which a corresponding rib l2 of the wheel 2 fits. 1

The disc 1 and the wheel 2 are further joined by filled lugs l3 havingradial ribs, next; to the periphery of said wheel 2.

Thus, a concentric attachment of the disc Ito the wheel 2 and a positive attachment of said disc 1, with respect to said wheel 2 are obtained in the circumferential direction, although leaving to said two elements, the possibility of expanding separately with respect to each other, in radial directions.

The disc 1, hollow in its central part, is closed on itsradial end by means of a light iron sheet plate l4, fixed to the edges of said disc I, by means of screws 15 for example. Said plate l4 -is shaped in accordance with a-cone, the outline Fig. 2 represents respectively in its left and right halves cross-sections of the upper half of said turbo-compressor, perpendicularly to its axis, along the lines 2 2 and 2 2 ofFig. 1,

Fig. 3 represents, on a large scalefa transverse cross-section through the paddles or blades and the parallelograms of the velocities which. characterize the operation of the apparatus,

Fig. 4 15a sectional view of one manner for at- Fig. 5 is a sectional view of an alternative manner of attaching a blade,

Figs. 6 and 7 .are respectively front and'sec-. tional views of another way ofattaching the'paddie, in accordance with the invention,

,Fig. 8 is a schematic'cross-sectionof a modifled form of turbine in accordance with the invention, but having both streams in parallel.

The form of impeller or turbo-compressor represented in Figs. 1,2 and 3 is mounted on-a drive shaft l-which may be,-for example, the end of an airplane engineshaft. A wheelv 2 made of a light alloy or any other metal, is fixed on the shaft I, by means of a key land a conical fitting. Said conical fltting [is combined witha drive washer Sheld by a stop nut 6 screwed on' the end a r of shaft l and positively secured.

A disc I made of a. light alloy, or any other lit) , characteristics of the apparatus power).

stream at the inlet of the apparatus. It further serves to shield nut'fi used for the mounting of the wheel 2 on the shaft l.

The wheel2 and the disc 1 which constitute the body of rotor 2| carry on their outer surface, circular arrays of paddles or blades I6 I 6 I6 for the disc, I and I1 11 .-for the wheel 2, called movable paddles or blades. The outline of said paddles (Fig. 3) I6 H is difierent for different rings, and according to the (speed and The paddles 16 I1 may be made of a light; alloy, brass, or another metal. They may be obtained by the transverse cutting of bars rolled to their outline, along the length of said cut elements. Round or polygonal stems 18 are machined, long' enough to permit the riveting of the paddles on the wheel 2 or the supporting disc I 1 (Fi 4). I

In the case where the paddles have a consider-. able length, or if the speed of the wheel is high,

' said paddles I6 are further maintained at their 'end by the riveting of stems IS on the rings 20 forming hoops (Fig. 5); 4

The paddles I,6-l'| .may also (Figs. 6 and 7) be fitted in the circular grooves 2| of the wheel 2, with'interposition of the intermediate parts 22-22: on which the edges of the'groove 2l are hammered down as at 23.

-In.the case of paddles havinga small projection, they can be'milled on -'the body of the wheel itself. p

- In any case, the paddles maybe hooped at their end with a riveted ring, as shown in Fig. 5. on a eylindricalbearmg part 23 of the wheel 2 is mounted a plate or cheek 24, made of a light alloy or any other metal, carrying on its internal face radial ribs 25 cast or stamped together with said check or fixed by welding orbrazing.

The cheek 24 constitutes the principal part of the stator; it is fixed to the frame 50 or to the case of the engine; it may even be an integral part of said case. t

On the outer face of said plate or cheek 24 two circular bearing parts 26-2l are machined, on which is fixed an annular discharge collector 28, made, for instance, of light iron plate which is connected to the engine inlet.

Tight connection between the plate or cheek 24 andthe cylindrical bearing part 23 of the wheel 2 is obtained by means of a rib joint 29 forming a tight packing.

The longitudinal play of the whole of the shaft l and wheel 2, with respect to the plate or check 24, must be less than the play between the padclleslli I1 and the wall facing them. To this end, the drive shaft I must be held longitudinally in the bearing next to wheel 2, so that the expansion of said shaft I, in the direction perpendicular to the stator, may be as small as possible.

' Opposite to the paddles I1 ll of the wheel 2 and fixed to the radial ribs 25 of the plate or check 24, a second stator plate'or check 30, made of a light alloy or another metal, is mounted.

Said second plate or cheek 30 of the stator is fixed to the radial ribs 25, for instance with bolts 3| passing through eyes 32 cast projecting over the ribs 25.

Said second check has a slightly conical shape. It carries circular arrays of stationary blades or paddles 3| 32 fixed in the same way as the movable paddles I1 I1 on the wheel fiend interleaved between said movable paddles l Said stationary paddles 3l 3| which are subjected to no stress due to centrifugal force, may be made of a metal of less strength than that used for the movable paddles I6 I1 Finally, the rigorously concentric'mounting of the cheek 30 on the wheel 2 is obtained by means of the stems 32 carried by each rib 25, and fitting in a circular groove 33 provided in the cheek 30.

The stator is completed with an external housing or cheek 34 made of a light alloy or another metal, forming ahousing for the stator, and be-- ing fixed at the periphery of the cheek 24, with bolts 35 and concentric fitting 36, for instance.

Said stator housing 34 carries, on its internal face, which is substantially perpendicular to shaft I, circular arrays of stationary paddles 31 31 interfoliated or mutually interstitially positioned between the rings of movable paddles l6 l6=I6 The housing 34 is continued by an axial tube 33 which constitutes an axial 'fiuid connection to outside the casing, and with flange 39, for the connection of the impeller or compressor inlet p pe The housing 34 and the cheeks 2430 constitute the body of the compressor stator.

The two stationary paddles: nearest to the pe riphery 31 and 3H, are attached by the above sion (or of a groove 4|, in which is tightly fitted a collecting ring 42 formed of two walls 42 42 perpendicular to the axis and of a cylindrical wall 42 joining theformer on the outside. The wall 42 -of the ring 42 is joined to the cheek 24 of the stator by a set of tubes 43, welded, screwed or rolled in the wall 42 Furthermore, said tubes 43 pass across the stator plate or check 24 and have a threaded part 44 extending beyond a fiat bearing surface provided on the outer face of the check 24 around the orifice.

A nut 45, screwed on the threaded part 44 and bearing against the fiat surface, insures the tightness of the assembly.

Finally, the stator housing 34 may be provided, on its outer surface, with ribs 46 for strengthening same and furthering the cooling of said v housing,

The operation of the above described apparatus is the following:

Assuming the rotor revolving in the direction of the arrow f (Fig. 3) consider a ring of movable paddles ll" near the shaft and the rings of stationary paddles 3l 3| located immediately adjacent thereto. The stationary paddles on the stationary inside ring 3|, (Fig. 3), whichare inclined so as to obtain the correct inlet of the fluid incident on the movablepaddles on the further out ring 3| act on the contrary as diffusor for 0 the ring of movable paddles I1, and as distributor for the ring of movable paddles Fi Each ring ll of movable paddles thus gives an independent compression, the whole of the concentric rings l'l creating, in series, all together, successive stages of compres expansion, should the device operate as a motor) another and permitting to obtain a high final I described means, such as riveting, to the wings of a tie-ring 40 of U beam section, made of .a

light alloy or any other metal. The inner cylin drical face of said ring 40 is-provided with One of the wings of the ring 40 is, provided with The gaseous fiuid thus sucked in by the axial pipe 38 of the housing is progressively compressed bythe rings of movable blades l6 IE IS IS on the disc I, then passing between the tubes 43, said fluid is brought back towards the axis of rotation, under the action of the pressure, through the passage between thefirst stator plate or check 24 and the second stator plate or cheek 30, said fluid being then radially guided by the ribs 25. The fluid then passes through the opening near the shaft of the second stator cheek 30 and is directed outwardly in a centrifugal direction into the rings of stationary paddles 3| and movable paddles l'I. undergoes a second series of successive compressions, caused by the rotation of the rings of movable paddles I! carried by the wheel 2. 'The fluid compressed to a maximum escapes into the discharge collector 28, after passing through the tubes 43 which constitute peripheral fiuidconnections to outside the casing.

Both faces of the rotor, constituted by the wheel 2 and the disc I, are thus used for obtaining two stages of compression added one to pressure.

Instead of adding, in series, said two stages of compression, obtained on each face of the rotor, said two compressions can be put in parallel so as to double the delivery of the apparatus, the finalpressure being that obtained with the paddles of one single face of the rotor; This double stream' compressor is schematically represented in Fig. 8.

It essentially comprises a stator composed of an inlet collector ii near to. the axis, of two conical cheeks 52 52 -carrying the rings of sta- Then, the fluid,

. tlonary paddles 31 3P movement, has for-consequence to decrease to- '0f said angle approaches unity and the value j-pr'ession on each one-of its faces- The angles (1 3 sion, the work done is:

temal power V and of an outlet collector 53.

The 'rotor is composed of a wheel 54 fixed on the shaft 55 and presenting, on each one of its faces, rings of movable paddles I6 I6 I1 5 l! mutually interstitially positioned or interfoliated between the rings of stationary paddles 31 37 ...3| 3l"ofthestator.

The two streams are conducted on allsides, of the wheel 54 in a symmetrical and centrifugal manner.

The power taken by each one of the ring units of the compressor of theinvention is expressed by:

. l5 W=(UV cos a UV cos (1) where p is the weight of fluid treated per second, g the acceleration of gravity, 1

U the velocity at the periphery of the rotating movable paddle, V the absolute velocity of the fluid at the outlet of the movable paddle, a the angle made between said first mentionedtwo velocities, 11 the velocity at the inlet of t e rotating movable paddle, X" the absolute velocity of the fluid at said inlet, -a the angle made between said last mentioned two velocities. L

It is apparent from Fig.3, that the inclination of the movable paddles, at the inlet, ahead of the movement, results in' giving angle u a value greater than 90, therefore, to give to the term (UV cos 02) a positive value. I

In the same way, the slight inclination of the movable paddles l'l at the outlet, ahead of the 40 wards zero the value of the angle a. The cosine of the term U V cos 0: increases and approaches the value U V The value of the angles of, a may evidently vary although being limited by the paddles machining considerations. I I

In the same way, the height of the paddles,

. projected on a radius, may also vary, the height of said paddles and their pitch being however capable of permitting an appropriate guiding of the fluid stream.

Numerical example.'-Supposing a rotor having a diameter of 523 m. m., rotating at 2500 R. P. M. and having 6 rings or stages of comare supposed equal to- 135 everywhere. The air delivery is supposed to be 1 kg. per second.-

For the respective rings or stages of compresnd 4,308 kgmsf for both facesy A wheel of an ordinary compressor, of same j-outside' and, inside diameterrprovid ed with radial paddles and rotating at the same speed, would have given, under the same conditions, an inof 500 kgmsper face of wheel, i. e.

power by using water falls,

1000 kgms'for both faces, 1. e. a power four times smaller. 1

The efliciency of the compressor of the in ention is about 0.90.- The internal power of 308 kgms, above indicated, corresponds, taking said eflici'ency into account, to an increase in pressure sufficient to restore at the inlet of an engine operating at an altitude of 4000 meters 9. pressure equal to that prevailing at the ground.

The apparatus of the'invention also presents the following technical advantages:

1. The internal efliciency of the apparatus is important, it reaches 0.90 while the lmown compressors have an efliciency around 0.70. The

mechanical efficiency of the apparatus is also high due to. the eliminating of gears and the reduction to a minimumof the bearings and surfaces of friction.

The overall efliciency of the apparatus of the invention oifers, for said two reasons, great advantages.

2. The heat g'of the ,compressed fluid is small for the reas us which cause the increased efflcicncy. In the case of airplane engines, this advantage permits high compressions with no risk of pre-ignition.

.3. The peripheral circumferential-speed of the rotor which, in known compressors, reaches 300 to 400 meters per second, is reduced, in the apparatus of the present invention, to about 70 meters for the same result.

4. Said moderate speed permits the direct drive of the rotor by the engine shaft end, which does away with step up gears, reduces the overall dimensions and the losses of energy through friction. I

5. Oil drawing'is suppressed in the case where the compressor is direct driven by the engine shaft.- v

6. The compressor. of the invention further permits, as in the known centrifugal compressors,

' to increase the .total compression ratio by ordinary means, such as the use of several turbine rotors in series, or the increase of the circumferential speed, by increasing the diameter or the speed ofthe wheel.

The invention extends, to the impeller devices described, either serving asturbo-compressors,

or, on the contrary, as turbine motor supplied with a compressed fluid.

The invention extends to the devices described,

Whatever may be the fluid utilized, steam, gas,

liquid. The invention is also capable of many applications and, in particular, of the following:

1. Steam turbines, 2. Recompression of lost vapors to recover heat,

3. Gas. or steam compressors in the refrigeration industry,

4. Low and high pressure compressors in the compressed air industry and aviation, 5. Small compressedair'turbines in the indu try of pneumatic tools and apparatus,

6. Internal combustion or other gas turbines, 7. Hydraulic turbines for the production of 8. Centrifugal pumps for all liquids, at low and high pressures.

I claim': I 1. In a rotary impeller unit, a substantially flat rotor having on each of its two radial faces a series of concentric mutually spaced ring arrays of rotor impeller blades, a stator comprising a casing surrounding said rotor and having two .inner radial faces each provided with a series of concentric mutually spaced ring arrays of stator impeller blades which are positioned to interstitially occupy the ring spaces between said ring arrays of rotor impeller blades, an axial fluid connection to outside said casing, peripheral fluid connections to outside said casing, said rotor and stator comprising path defining means for .defining a fluid path from said axial connection radially outwardly through a first said series of ring arrays on one rotor face, thence radially'inwardly through a clear channel inside said casing which extends along the inside of the outer wall thereof, and thence radially outwardly through a second said series of ring arrays on the other rotor face to said peripheral 'extemal l5 connection;-

stator having-two adjacent substantially radial plates one of which forms a part of the external casing and the other of which constitutes one stator inner radial face carrying a series of ring arrays of stator impeller-blades, and said two adjacent stator radial plates forming between them said clear channel.

EMILE DUPONT.

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