US2386896A - Balanced compressor - Google Patents

Description

M. F. HILL ETAL BALANCED COMPRESSOR Oct. 16, 1945.

Filed Sept. 1, 1958 7 Sheets-Sheet 1 INVENTORS Oct. 16, 1945. M. F. HM Em 2 38 896 BALANCED COMPRESSOR Filed Sept. 1, 1938 7 Shets-Sheet 2 INVENTORS w c1 .uau

Oct. 16,1945. M. F. HILL ETAL BALANCED COMPRESSOR Filed Sept. 1, 1938 7 SheetsSheet 3 INVENTORS M mmu Oct 16; 1945.

M. F. HILL EIAL BALANCED COMPRESSOR Filed Sept. 1, 1958 7 Sheets-Sheet 4 212 an an al A lol INVENTORS Oct. 16, 1945. m. HILL Em 2 386,896

BALANCED COMPRESSOR Filed Sept. 1. 1938 7 Sheets-Sheet 5 I75 I i INVENTORS M. F. HILL ETAL BALANCED COMPRESSQR @izfi. 16, 1945 Filed Sept. 1-. 1938 7 Sheets-Sheet 6.

' IN VEN TORS M.F. HILL ET AL BALANCED COMPRESSOR,

Filed Sept. 1, 1938 7 Shets-Sheet 7 Patented on. 16, 1945" UNITED STATES PATENT OFFJCE BALANCED COMPRESSOR Francis A m, 2nd,

Westport, Conn.

toothed sears. one within and eccentric to the other, operating as a displacement mechanism for pressure fluids, particmarly for the compres sion and expansion of gases, and hold balance systems tending to float the rotating members from their bearings so that they may operate under pressures greater than the hearing surfaces themselves can carry. Many of its features are useful in connection with liquids.

In the patent to Myron F. No. 1,682,564 a displacement rotor or near mechanism was shown for such purpose in which the outer rotor was driven by a motor shaft acting as a drive device in order to maintain the tooth contacts tight, regardless of backlash whether intentional or due to wear. These tooth contacts separated chambers between the teeth while theywere closing in a compressor (or opening in an engine) and the eflicienoy of the mechanism largely depended on keeping the contacts tight, since openings between the teeth permit pressure gases in a chamber to escape to lower pressure chambers without accomplishing intended results.

One way of maintaining such contacts tight is to connect the drive device to the outer rotor, and the patent above mentioned employed .a driving plate or hell which was mounted on a motor shaft and carried an outer rotor near its outer perimeter. These parts rotated in :a casing. When used for compressing air to higher pressures, to 100 lbs. .i'or example, the pressure Q seeped out through the running joints into the casing and to the hack of the plate, reroing the rotors against the trout cover plate, causing friction, heat, and loss of power; and. with the lubricant adopted tor substantialiy isothermal air compression, causing it to m and retard operation. Various eflorts were made to overcome these obstacles, such as pressure balancing areas, thrust hearings, etc, in that mechanism they proved too and uncertain to be relied upon. Journal hearings were also inadequate for the heavy "work the rotors were capable oi mentor-name, due to the necessity of tight bearing his for centering the rotors, and the inevitable. heating and "freezins that ensued. 1

Our invention aims to solve these problems and provide means to enable the rotors to success-' ly periorm the high pressure work of a piston and cylinder displacement mechanism now generally used for these purposes.

In the patent to Myron F. Hill, 1,682,565, the rotors were mounted between two side walls 1, 1933, Serial No. 227.954

which are secured to each other, so that they received equal gas pressures atrom the roior chambers between containing gas pressures varying from in chamber.

members with relaifion to the rotor that it drives,

to prevent the motor from lacing tipped by the drive device out of its plane of action. "Ihe construction in the shove mentioned patent did not accomplish this result since the hearings on one side of the shaft would loose so ems would not normal to the plane of action provided for the rotors. caused the rotor to cant, which resulted in point contacts between the teeth of the two rotors instead of I necessary line contacts across teeth .lrom one side wall to the other, allowing escape of pressure gases between at either side of the point of contact. sheet of such crevices in liquid pumps i of minor import, in compressors, particularly at high pressure they ds-v stray emclency.

One way not the only so! getting and proper tooth action is to drive the outer rotor Toy a cylinder acting as a pulley or as an armature shafit, or Toy some suit-- able device mounted hearings on [each of the center line oi the rotors, preierably oi the tooth chamber sidewalls. Both the drive rotor and the driven rotor then rotate in the same plane. Another method of securing result appears later.

order to float rotors (ofi their hearings, liquid pressure from the higher onessure port or passageway, the con-- ducted to recesses or channels which may be located between a plurality of landings or limes which constitute the proper. and on that side of the shaft or serial support major thms't or load resulting the pressure in the motor chambers. Becesses or on the opposite side of the axial supmay be connected to low presume passageways or ports to prevent the aommmlemon of nressin'e which would counteract the By this system of balances the loads upon the hearings themselves is greatly-reduced.

The driving hell on the drive shah; extended Another feature of our invention is a displacement mechanism capable of running efficientlyat either low or high speeds,.acoording to the power and speed applied, without manufacturing different sizes, and adapted todo the'work of which is mounted inside a hermetically sealed casing, the armature preferably being divided in two, one half on each port plate, to balance electrical end thrust. Each side wall or port plate is secured to the other through the shaft which is mounted on bearings outside of the port plates. The pinion or inner rotor is caused to revolve around inside the outer fluid displacement member or gear. In this way both an electrical balance and a compression balance are provided. While this mechanism is described-primarily 'as .a compressor it is obvious that it may be reversed withrespect to the ports and act as a motor; and when an electric device is incorporated it becomes a generator.

The types of rotors or gears described and a claimed in the patent to Myron F. Hill, No. 2,03 l,-'

888, or No. 2,991,317 may be used in our invention.

In the drawings: Fig. I indicates a displacement mechanism with a motor belt drive, and mounted on a horizontally disposed reservoir.

Fig. II is a longitudinal section of such a compressor on line II-H Fig. I.

Fig. III is a section, on line III-III of Fig. II showing an end bracketwith fluid passageways, reduced in size.

Fig. IV is an inside view of one of the port plates on line IVIV, Fig. 11.

Figs. XXI, mm, XXHI show other bearing details, of the form of Fig. XV.

Fig. XXIV shows a motor (with the compressor inside) mounted on an air storage tank.

Fig. XXV shows a section on line XXV of Fig. XXIV.

Fig. I shows a compressor in a shell l, driven by a belt 2, and a pulley 3 on the shaft of a. motor 4. The compressor and motor may be mounted on a storage'tank 5. Figure I shows a left hand view of the compressor shown in sectional elevation in Fig. II.

Fig. II, shows the compressor shell or casing I, driven bythe belt 2. Inside the shell (and driven by it) is secured the outer rotor 6, which drives the pinion rotor l. The rotors 8 and I run between fixed sidewall or port members 8 and 9. The compressor shell I is carried by bearing members l0 and II journalled at [2 and I3, which thus also carry the working load of the outer rotor 6. The pinion rotor is journalled on an eccentric bushing M, which has suflicient axial length to provide suitable running clearances for the rotorsfi and I. The stationary port members 8 and 9, eccentric bushing l 4, end bracket lfi, and collar I 9 are fixedly mounted on the shaft'l5 which may be a stationary bolt. The left end bracket l5 contains the low pressure passageway I1 and the high pressure passageway l8. At the the nut 22 on the shaft l5is tightened solidly it fastens all the stationaryparts l6, 9, l4, 8 and i9 Fig. V is a section on line VV, Fig. II, show- -ing an end view of the rotors or gears.

Fig. VI is a section on line VI-VI of Fig. II

showing passageway details of a port plate.

Fig. VII is a sectional elevation of another form of our compressor inside an electric motor, with the outer gear member stationary, with asplit armature and 'with the inner rotor revoivingon two centers around inside the outer rotor or gear member.

Fig. VIII, the right half shows the outer gear member of the form 01 Fig. VII fixedly mounted in a stator. The left half of the figure shows the half armature of the form of Fig. VII mounted on one of the port plates.

Figs. IX and X show port plate details or the formofFig.VII'

Figs. x1, x11, x111, XIIIA, and xirv show rigidly together'by thrusting them towards the bolt head 23. Member 6 has a running fit between port members 8 and 9. Bearing members ill and H have enough looser side wall running its as to avoid contact with both members 8 and i9, and 9 and I6 respectively.- This shaft may also have additional support at its other end as indicated by the bracket 24. The stationary shaft l5 and the member l9 may be one piece if desired. e

In operation the shell! is turned by the belt 2, which causes the rotors 6 and l to rotate.

. Air or gas is sucked in through the passageways passageway and bearing details of the form oi Fig. xv is a sectional elevationof Fig. xvr on line XV-XV.

Fig. XVI is a side elevation of one form of our invention shown in Fig. XV with theright hand Fig. XIX is a detail of the pinion rotor bearing of the form of Fig. XV.

' Fig. XX shows am an ed view of the frinies" used in our bearings of the form or Fig. XV.

and the hous- IT, 25 and into the intake port 26 (Figs. II, HI, IV) and the opening rotor chambers 27 and 28 (Fig. V). The gas is then compressed as the chambers readh the positions 29 and 30f and finally expelled out thru the discharge port at 3|, high pressure passageways 32, and Hi. This port has alength sufllcient at Ma to overlap a rotor chamber in which the pressure has been raised to the desired degree. It should be separated from the intake port 26, (Fig. V) by a travelling tooth contact between the rotors or gears across full mesh, and ends at about a point the length of a chamber from where the contacts between the teeth begin to open, allowance for rotational speed being desirable.

From i8, the compressed gas or air may o to a storage tank 5 (Fig. I) thru the pipe 33. The compressed gas may be drawn oil from the tank thru a pipe and valve 34.

A pool of liquid used for'cooling gas (air for example) during compression, for pressurebalancing and for lubricating bearings is provided in the tank 8 (Fig. I). I V

' We prefer to circulate liquid through the running parts of our compressor by using the pressure of the compressedgas or air to send-the liquid first to the three pressure balancing zones 5 and bearings at l2, l3 and 35. For this purpose we put enough liquid in the tank I to always more than cover the lower end of the return pipe 38 (Fig. I), the upper end of which may be screwed or sweated into the shaft II at 31 (Fig. 11). The air pressure above the suri'ace oi the lubricant in the tank sends the oil into the passageway 38 and into the bore of the shaft"; In Fig. V the duct 40 connects bore II with the circumferential groove II to lubricate the eccentric bearing at 35 for the inner gear I. This forced feed liquid is'also introduced into the flotation channels between the riilles of the pinion bearing under the rotor chambers compressing gas and resists the resulting thrust of the pinion against the shaft on the compression side. The angular length of the groove 4i determines the flotation,

area of the zone to balance the radial thrust of the mean eflective pressure in compression chambers I, II and 30a.

In order to prevent thispressure from creeping around the shaft so far as to offset this "hydrostatic balance, the intake port may be extended inward as indicated at 42 in Figs. IV and V to uncover the ends of the recesses between the rifles on the inner bore of th pinion rotor and assisted by the angular groove Ma, release any pressure in them. These recesses and zones are discussed more at length below;

Figures IV and VI show how the oil is conducted through the passageway G3 to the grooves 44 (also Fig. 11) inthe port members 8 and 8.

Becaus compression in the closing chambers shaft, the load on bearings i2 and I! has to be balanced by liquid pressure channels on the axial support on the sleeves or hubs of the side walls diametrically opposite the discharge port and compression chambers. Holes l and 46 providing a vent to the intake passage 26 at each end or the grooves ,serve to prevent the high pressure liquid from extending too far around the axial support and upsetting the hydrostatic balance.

The liquid acting now as a lubricant leaks from the recesses or channels oi the high pressure zone toward the low pressure zones between the extent of cooling. The gas or air may be drawn oi! at 34 as above mentioned.

tends to thrust the outer rotor away from the A regulating valve for the lubricant may be inserted in the Pipe 36 at as (shown diagrammatically in Fig. I) and may be hand regulated or automatic as elsewhere described.

- Figure VII shows our compressor inside an'electric motor, having casing members and 58 with the outer gear 51 held stationary inside an electric 7 shown the stator with 12 poles. The hermeti cally sealed housing members ti and 62 prevent injury to the windings from refrigeration gases either during operation or when being repaired. The outer edges of th members 6i and 82 are clamped in the casing joint by means of bolts to, and the inner edges may be welded at 51a to the outer gear, 51. The armatures comprise copper frames", 64 with iaminations of magnetic iron Na and 64a in the holes "b and lb,

Fig. VIII. These poles vary in number as compared to the field poles in the manner well known to the electrical motor art.

The armature is composed of a sufllcient amount of magnetic material to cooperate with the stator efliciently. In order to avoid electric end thrust we show the armature composed of two members 83 and SI, mounted on and keyed to port plates 85 and ii. These port plates are keyed to the shaft II. On the shaft and keyed to it is an eccentric bushing 69 on which-the pinion gear 10 is free to rotate. This bushing 8! is sufliciently thicker than the gears I1 and III to provide the slight clearances between them and the side port members '5 and CI tor-an eiiicient 45 free running compressor.

the rimning surfaces and into the intake port 28 p and the balancing dummy intake port 41 in the port member 8. Any liquid leaking outwards from the pressure channels between the riilles of bearings l2 and I3 is diverted by the smiling boxes or seals 48 and 49 into the cylindrical grooves It and ii from whence it is sucked back through passageways 52 and it to the intake passageways 2i and it (where inrushing air shreds it into a sort of rain) and ports 26 and 41 and into the opening rotor chambers where it new acts as a coolant to suppress the rise of temperature which would result from adiabatic compression.

It willthus be seen, that a mixture of coolant liquid lubricant and compressed gas passes through the rotors and is discharged'out at the discharge port II, through passageways 32, II, and pipe 33 and into the tank 5, where the coolant flnds its way to the bottom to repeat its circuit. Thus in this circuit the liquid has actedas a pressurebalancing agent in the pressure zones, as a lubricant for the bearing riflies and areas around the pressure zones, and as a coolan on the clearance in the journal bearings and the .leakage from them which, assisted. by the pres- When the nut II is tightened, the rotating parts 88, 88, and 69 are thrust against the shoulder 12 and rigidly fixed in position.

The armatures '3 and it drive the port plates 5 II and 66, the shaft and the eccentric bushing it which cause the pinion gear ill to be rolled around inside of the outer gear 51. so that in veilect the outer gear 51 causes the inner gear II to rotate-on its own center while being carriedaround the shaft center by the eccentric II thus providing relative rotation between the rotors.

The left half of Figure vm shows the misture it mounted on the port plate 58 and shaft This eccentric throw oi the pinion II creates VILVIILand x).

The axial supporting shaft 81 has outboard end bushings it and II which may have end closur and bearing members 18 and 19. The shaft has three interior passageways II, II, and 82. Passageways ii and 82 are connected to- Bother as shown in dotted line in Figure VII.

sure created in the rotor chambers, determines 76 In operation, gas is sucked in through the passageway. II in the casing member 55, the cylindrical groove ll, the intake port I! (Figs. VII, 1x and x) and into the opening rotor chamports BI and 88 in port plates 63 and 65 cooperate in discharging gases from the compressor. Having been compressed the gases and entrained coolant liquid in them are'discharged through ports 31 and 88, into passageways 09 and 90 and into the shaft passageway 30 thenceout into the oil and gas separating chamber 9| issuing through the hole 92 which is of course rotating with the shaft at motor speed. Separation of the lubricant from the gas may be assisted by the cupped bafiie plate 94 and disc 93. The passageways 30 and 8| may be plugged at 86 and 91 as indicated in Fig. VII. The baflle plate 94 may have holes near the shaft at 95 if desired. While we have shown only two such baille plates it is obvious that any number may be added so as to get emcient centrifugal liquid from gas separation. The

. clean gas then emerges from the compressor casing at 98 ready for useeither to blow up tires, or for a refrigeration cycle.

After separation the pressure in chamber 9| forces the liquid through the passageway 99 and into the cylindrical groove I (Figs, 'VII and XIV) around the shaft, through the hole IOI' and V v into the shaft passageways 8| and 82. The bushings I5, 11, and the recesses in the eccentric bushing 69 receive pressure balancing liquid from the passageways 8| and 82 by way of ducts I02, I03 and I04 respectively, (Figs. VII, XI, and XIII). grooves I02a I03a and I04a (Fig. XI) feeding channels I02b, M31) and "Me between the riilles of the various bushings. Each end of the shaft is subjected to the same discharge pressure so that there is no unbalanced axial thrust and the whole compressor is thus in substantial hydrostatic, mechanical and electrical balance.

The intake ports may have undercuts at I 05 Fig. 1X to uncover the ends of the channels I04c in the eccentric bushing bearings to prevent the force feed liquid pressure from creeping too far around the central shaft.

The outer bearings may be relieved from a similar unbalance of pressure by such grooves as I06 Fig. XEV and I01 Fig. VII which allow the liquid to escape from the channels into the low pressure areas around the nut II and the shoulder I2.

As the liquid seeps from the channels and from the spaces between the rotors or gears and their port plates it is flung out into the casing from whence it drains by gravity into the casing de-. pressions I08 and I09, through the passageways H0 and III and 2' into the intake passage 93 fromwhence it may be sucked back into the compressor with the incoming gases. V

If the chamber 9I is unable to store enough liquid for operation, it may be tapped off as indicated in dotted. lines at II 3 into some storage chamber (not shown) and then returned at full pressure and sprayed into the intake at H4 (dotted lines) and also returned at full pressure to the duct 99 for lubrication and flotation. Duct 99 in this instance would have rro direct connection with duct I I3.

-In Figure XV is shown an outer housing I20 having ribs I2I within which is mounted a stator of an electric motor, having for example laminations I22, holding coils I23, I24 in circuits I23a escapee i p 'The coils I23 may be for therunning current and I24 for the starting currenta These coils may mounted upon a steel or iron ring I 26. The outer Ducts I02, I03 and I04 empty into the rel cage 'type of armature I25, such an armature having greater inherent strength than a wired armature.

This armature or motor rotor I25, preferably of laminations inserted in a copper frame, may be rotor may be integral with the ring I26 or keyed to it at I21.

As the armature I25 rotates it carries with it the armature ring I26 and the outer rotor I28.

This triple unit may be mounted upon side bearing members, I29 and I30 which are provided with suitable radial eccentric flotation channels and bearings at I3I and I32. Those here em-- ployed will be described more in detail later. The members I29 and I30 may be of cast iron and are preferably keyed to the armature ring I26 at I2'Ia and I211). The inner rotor I33 may be journalled upon a concentric bushing I34. The bearings I3I and I32 in members I29 and I30 may be centered upon the axis I35 (Fi XVI) of the outer rotorwhile the holes fitted to the fixed shaft or bolt I36 are centered upon the axis I31 of the inner gear. The bushing I34 may be of bronze or hardened steel, or of any,o ther suitable bearin material to cooperate with the rotor I33 that turns upon it, it being understood that the rotor'l33 may be, and preferably is of hardened steel, its bore being provided with'channels I38 (see Fig.

" XVI) separated by rifiles engaging the bushin similar to those shown in Fig. XX, riding upon liquid films between the riflles and bushing, de-

' scribed more in detail later.

The bushing I34 is longer axially than the rotors I28 and I33 toprovide film spaces between the side walls and the rotors. Sometimes the bushing exceeds the rotors axially by from one ten thousandth to one and a half thousandths of an inch according to conditions of use; and when the side or port members I39 and I40 are bolted solidly against its ends, by the bolt I36. their inner walls leave the rotors free to rotate.

The port members I39 and I40 may be of any suitable material, preferably magnetic, so long as their inner walls cooperate in running qualities with the two gears.

The bushing I34 and port members I39 and I40 are held in correct relative location by the pins MI. The bushing is centered on the bolt I36 which in turn is tightly fitted to the side port members I39 and I40 and to the cover members I42, and I43. The bolt is keyed at I44 to the latter to prevent its rotation.

By'this arrangement all lathe work is concentric except the bores of the members I39 and I40 which alone have accurate eccentricity (with re- "spect to the bearings I3I, I32) equal to that of and I24a -(Flg. XVI) suitable for two or more Phases of an alternatlngcurrent, one orwhich in a small motor might be a spli Ph the rotors.

The outer edges of the covers I42, I 43 may be bolted, riveted or welded to the casing I20 in any .well known manner, in accordance with usual The'armature I25, Fig.'XVI, shown in the drawings may have twenty-nine squirrel cage inductive copper bars- I45 (Fig. XV) set up mechanical y and electrically in plural phase motors, perhaps of the split phase capacitor supplied type, which have no switch members within the motor. While this may be one form, it is well within the spirit of starting and running, the other for running mainly, all wired as indicated in broken lines. The coils I28 may carry the split phase and the coils I23 may carry the main current from one wire of a three wire system. This arrangement provides 1880 R. P. M. Any other speed may be provided includinga return wire. Three wires for this equipment from the capacitor enter the casing through gas and pressure tight insulated entrances, indicated at I48. These wires are connected to the coils in the usual manner for such motors.

As the armature I25 drives the outer rotor or centers of the arcs of the teeth and of the toolgear, that gear drives the inner rotor or gear I33 which rotates upon its journal on the bushin I34 opening and closing tooth spaces between the teeth. Since the outer gear drives the inner gear the teeth makethe fluid tight engagement where the chambers are closing,- an arrangement providing also a longer suction entrance I49 (Fig. XVII) to the chambers that are opening than when the inner rotor drives the outer rotor.

Our continuous contact contours for holdin graduated pressure in successive chambers between the suction port I49 and the discharge port I50 provide high pressure ranges. g

The discharge port may begin at I5I (Fig. XVIII) for low gas pressure and at any point, such as I52 for higher gas pressure. I52 should be located to connect with closing rotor chambers at the point where the desired discharged pressure is attained in these chambers.

The port ends at full mesh are separated preferably bya toothdriving engagement at a little less than the angular length of a tooth and tooth space. The arrow I58 in Fig. XVI indicates this distance and location when the above mentioned rotors are employed, the engagement occurring partly upon the opening side of a line through the axes I55 and I31 of the rotors (Fig. XVI) With such rotors, the teeth maintain tight engagement regardless 'of wear from the end I54 of a crescent area to the end of the driving range near the point I55.

The suction port may extend from the point I55 to I54 though to shorten it at either or both ends does little it any harm to its cooperation with the rotor chambers.

The open space between the teeth at open mesh extends from about I58 to. I54, these points being determined as a rule by the intersections of two circles, one touching the inner tips of the outer rotor teeth and the other touching the outer tips of the inner rotor teeth.

Our rotors or gears are designed as follows:

Suitable circular arcs for the convex outer tooth faces are first decided on, and an inner mating tooth generated by it usinga Fellows ear shaper if desired for generation purposes.

tioziih may be repeated to generate the other four During generation, both blank'and tool rotate upon the axes I35 and Ill, one complete rotation of the tool generating one tooth space in the blank.

The outer rotor merely has repetitions of the selected arcs making up the tooth form. The

have to be well outside of the outer pitch or ratio circle, at a. distance determined most easily by experiment. The proportions shown in Fig. V21 are about right. It the centers or the arcs are too near the ratio circle; the tool will undercut the portions of teeth engaging from I58 to I55 ruining the rotors. A slight amount of back lash, perhaps a couplqthousandtbs of an inch, so that teeth ma not wedge at full mesh, in case of uneven expansion due to heat, is desirable. This may be accomplished best by regenerating the inner rotor, after indexing it a degree or two.

The bottoms of the tooth spaces of the outer rotor gear should clear the tops of the Inner teeth in every position across two of an inch.

In M. F. Hill Patent No. 2,031,888 are shown and illustrated the latest form of rotors having a difference of one tooth. In those rotors a full open rotor chamber has a total depth of four ratio. Sincethey have 8 by 10 teeth they have greater durability and driving efficiency than the v 6 by 7 rotor and yet being based upon a 4 by 5 ratio in a given diameter have a greater depth of chambers due to the greater eccentricity.

A fair comparison of these new rotors would be with a by 9 rotors involving the principle set forth in Patent 2,031,888. Those 8 by 9 rotors would have an eccentricity of slightly over half that of corresponding 4 by 5 rotors and when the relation of the total rotor diameter is taken into account the volumetric capacity of these 8 iacent tooth of the outer rotor. I In fact five alternate .outer rotor teeth engage four alternate pinion teeth and the other four of the pinion are engaged by the remaining flve teeth on the outer rotor. In other words this maybe a duplex system of rotors approximately doubling the capacity of an 8 to 9 pump with equal driving efllciency.

' The driving relation is much the same as in two The backing oil gear of the Fellows machine is one tooth division-45 for 8 teeth-the operasets of 4 to 5 rotors with staggered teeth. Such a staggered system might be used with a partition between the rotors, and ports in the partition to both rotors, and port plates on the outer sides of the rotors.

These improvements depend upon a diflerence of two teeth as distinguished from a diflerence of one. 7

If a difference oi three is desired the relative capacity is less and the ratios are multiples of full mesh a thousandth or s 'ordrmnyithnipesreplaclng way "I menflmedfabove. I Duetothehighpressureexistingaboveth'sur-I face oftheliquidbath fll andthe lowpressure rotor which has been cut into, to provide a tooth space; and the correspondin P rtion of the pinion' tooth spaces is occupied with the inserted tooth. The lost radial displacement depth of the portions of the tooth and tooth space which have been so altered is but a slight fraction of their original total depth and height respectively because of the original flatness of the curves where altered. The widths of the teeth are preferably age of high pressure gas across the ends of the teeth is checked. These slots I59 tend to leave films upon the side walls of port members I39 and m which act as films for the outer rotor teeth preventing leakage of gas over their ends.

This film seeps over the ends of the outer rotor and into the space around the members I29 and I3! and inside the armature ring I26 from I whence it assists in lubricating the journals m and I 32 in the low pressure areas and then draining into the low pressure region within the easing members I42 and I 43. The liquid drains downward to the bottom regions I80 and I6I in j Figure XV which are interconnected vby the groove I82. a

In functioning, the gas .to be compressed enters the casing at I83 and is sucked through the motor parts, cooling them, and is then sucked into the bottom passageway at I and up through tor. Liquid then enters the hole I15 in the bolt I36 and by means or the holes I18 and I11 lubricates the bearingsand fills the flotation recesses in the high pressure regions at HI and I82 of parts I28 and I38 respectively. The holes I18 and I11 are diametrically opposite the discharge port I 58. Thus liquid pressure to provide a counterthrust to the radial pressure on the inside of the outer rotor compressing chambers, gand the balancing areas in these channels may be so proportioned by means of grooves I18 and I18 as to oppose or balance the radial thrust in the outer rotor. Two similar holes I88 and I8I force liquid into the above mentioned grooves I82, I83 and slots I59 of the pinion and also into that part 01 the pinion bearing under the compressing chambers of the pinion so that it too has a balanced radial thrust. For this purpose the grooves I82 and I88 (Figures XVI; and XVIII) are widened at I and I85 respectively so as to introduce the pressure into the channels between the rimes in this region. On the low pressure side of the pinion bearing the channels are connected to the intake passageway I64, by passageway 885a, Fig. XVIII, so that this pressure cannot creep around the shaft to upset this balancing function. Similarly channels in bearings HI and I32 on the sideopposite to that sustaining the major radial thrust maybe open at their-outer ends to the a i g I InFig. XX is shown an enlarged view of the the casing I43 and into the intake port at I49.

Any liquid that may have gathered at I80 or "I is sucked withrthe gas up into the intake port I48 thus preventing the liquid level from rising higher than the opening at I and so obstructing the rotation of the or soaking the stator coils.

The compressed gas and excess liquid is discharged through the discharge port I50 (Fig.

mi into the passageway I85, through the check valve I86, and, at I61 into the high pressure cham;

ber I68. As indicated at I61 this high pressin'e gas enters thischamber I88 tangentially being choked so as to setup a swirling action. This swirling causes the liquid to be thrown out against the walls I" where it drains into the bath "I;

preferably in a cylinder standing on end, actingv side walls. ,The comprmsed gas may be-drawn oil at "I above the liquid level and then pass through my usual refrigeration cycle or cooling coils and expansion chamber before returning to the intake at I. The ball check I" prevents compressed fluids from blowing back' into the intake I48, through the rotors or causing themto' withinthe compressorcasingthlslicuidisiorced upward for bearing lubrication and hydrostatic i l cingastollowsz' yIfltheliquid Eaving entered isiorceduptopreieri ve m electromag- V i having metallic contact with its hearing. A pluas a pressure storage container. If'cooling is de the liquid is cooled as it drains down the form of channels and riflies I prefer. The hearing shaft is'indicated at I86. The riflles I81 are between the recesses or channels I88. The rilfles have two surfaces, I89 which may be tangential to the curve of the bearing shaft I86 and the arc portion I90 which has a circular curvature cooperating with the shaft surface I86. The bearing efiect is similar to that of the Kingsbury thrust. If the riflle member travels in the direction of the arrow then the liquid supplied for compression first enters the space between the tangential portion'of the riille and is then swept onto the are so that the rotating member tends to ride continuously upon a film of liquid without 'rality of riilles provide as many bearing areas.

The'friction load on the bearing under a given set of conditions is determined largely by the number and width of the recesses. The fit between them and the shaft should be responsive to the exigencies of the hearing. The material of whichthis bearing is made is anon-friable material and preferably tough and hard to resist damage when particles of foreign grit enter. -In

- order to prevent excessive now the parts I28 and I30 may have bearing shoulders or hubs IQI and I82 respectively which substantially reduce such flow into the low pressure regions to that required for the functions of bearing, balancing and as o l ns enum t *In Fig. is shown an air compressor system ior' compressing air and cooling the liquid which absorbs the heat of compression in the rotor cylindrical tank or storage reservoir 283; The

\compressor discharges air mixed with a mist, my r 7 troduced at the intake, through the pipe in into netically controlled and diagrammatically 'illustratcd by solenoid I 14 which is in circuit with the motor and said valve is closed normally and momentcui-rentpassesintothcmoat ZOI-(FIg. XXV) choked so that the air andmist are caused to whirl around inside thetanhthrowingthemlstoutwardlybyccntrii- .ugal force against'the inner wall of the tank.. downwhichitdrainsintothepoolatthebottom.

chambers. The motor 2", operating a comprese The wall absorbs the heat from the liquid and delivers it to the surrounding air. The liquid in the bottom of the tank,.under pressure of the compressed air, is forced through the strainer 206 and up through the pipe 201 to the compressor, where it enters the rotor chambers in a comminuted form as mist and repeats its cooling function, and enters the channels inthe bearings as described. An exit 209, having a valve at 208, provides for the use of the compressed air.

In Figs. XXI, XXII, and XXIII I show another form of my bearing.

In Fig. XXI is a shaft 2), a casing 2H,.a

rifled combined pressure balancing and bearing.

bushing 2l3, having bearing rifles and pressure zones of channels with confining end ring members 2|2 and 2| 4, undercut at M6 and M respectively. (Figs. XXII, XXIII.)

Pressure forces oil or other liquid into the passageway 2H, and undercut groove 2l6 (Figs. XXIII and XXI) extending across the ends of a series of rifles and into the channels (see I88 Fig, XX) between them. The rotation of the shaft then sweeps theliquid from the channels onto the bearing rifles or landings (see I86 Fig. XX) thus causing the shaft 2l0 to ride on a series of liquid surfaces on the riflesunder hydrostatic pressure. The length of the are shaped groove 2l6 determines the high pressure area, which is designed sufiiciently large to meet load requirements.

In order to prevent hydraulic bearing area pressure from creeping so far around theshaft as to offset the load balancing pressures from the groove 2l6, another groove or undercut 2l5 with an escape passage ii to low pressure is provided. The groove 2l5 extends over the end of a suflicient number of channels to satisfactorily unload the zone where needed;

While not absolutely necessary, I prefer that 40 the lubricant'be forced in at oneend of the zone,

being connected by a duct to said high pressure port, and low pressure regions between said support and rotors, and opposite to said high pressure areas, having a duct connection to a low 5 pressure region; whereby varying fluid pressures in said rotor chambers create opposing forces to corresponding mechanical pressures upon said bearings.

2. The combination claimed in claim 1, in

10 which the low pressure duct connection acts-as an escape connection for liquid leaking from the high pressure areas to the low pressure region, said escape connection leading to the low pressure port, whereby shaft seals or packing are rendered unnecessary.

open and close during relative rotation of said fluid pressures in said chambers during opening rotors, members providing ports to receive gas from and discharge gas into said chambers, said ports being so proportioned and located with respect to said chambers as to provide varying or closing thereof, said teeth havin contours maintaining continuous contacts between said chambers, said chambers during opening or closing containing said varying fluid pressures and being kept in sealed relation by the driving contacts between said teeth to check air or gas leakage under pressure from one to another while performing pressurefunctions, a support for said rotors providing said eccentric mounting, said support including relatively fixed pressure conthence into the high pressure channels, thence over rifles and to the low pressure channels, and

then allowed to escape at the other end inside of the ring. The exit M8 is so located above the shaft that when the shaft is stationary, there is n0 tendency for lubricant to drain through it away from the zone. Close running bearing clearances at the ends of the channels, prevent the zone from becoming completely. dry during periods of idleness.

What we claim is:

1. In a mechanism for operation on or by fluids, rotors or gears mounted eccentrically to each other, one within the other, said rotors having teeth forming chambers between them which, open and close during relative rotation, said teeth havin contours maintaining continuous contacts between said chambers while performing fluid pressure functions, a support forsaid rotors providing said eccentric mounting, said support including pressure confining side walls closing said chambers at their ends, high and low pressure ports connected alternately to said chambers for supplying and receiving fluid for said operation,- bearings for said eccentrically mounted rotors disposed along said support to prevent said rotors from tilting at angles to each other, high pressure fluid areas between said support and rotors said areas located between said support and rotors, on both sides of a middle plane thru said rotors normal to their axis, and

filling side walls closing said chambers at their ends, said side walls having a fixed relation to said support, and means to supply mist to said a coolant to check change of temperature during variations of gas pressure in-said chambers, said chambers, tooth contacts and ports being sov located and adjusted as to prevent liquid locking or choking between high and low pressure ports at full mesh.

. separated by centrifugal force.

5. The combination claimed in claim 3, said rotors having a difference of two in the numbers of their teeth thereby leaving a'crescent space between the teeth at open mesh, said low pressure port connected to said crescent space to increase the ease of passage of low pressure gases thru the low pressure port.

6. In a mechanism for operation on or by gas and liquid, rotors or gears mounted eccentrically to each other, one within the other, said rotors having teeth forming chambers between them which open and close varying gas pressure between them, said teeth having contours maintaining continuous contacts between said chambers during opening or closing of said chambers to check air or gas leakage from a chamber containing higher pressure to a chamber containing lower pressure while performing pressure functions, said teeth having a difference in their so proportioned as to substantially balance the radial mechanical pressures of said rotors upon said eccentric bearings, said high pressure areas 76 of, high and lowpressure gas ports and passagenumbers .of teeth greater than one, a support for said rotors providing said eccentric mounting, said support carrying side walls for saidrotors closing their chambers at the ends therero'tor'chambers as their pressures vary, to act as ways connected alternately to said chambers and disposed angularly about said support so as to be separated by chambers varying in their pressure, bearing members for each of said rotors between said rotors and said support disposed axially of said rotors to maintain line contacts between said teeth from one side wall of said rotors to the other side wall or said rotors.

7. The combination in claim 6 havingmeans to supply mist to said chambers to check variations of temperature as their volumes and pressures vary.

8. The combination claimed in claim 6 having pressure areas between said rotors and said support supplied with fluid or liquid pressure from said high pressure port, said areas located to relieve the radial mechanical pressure upon said hers. I

port and between it and said rotary members 10- 'cated to oppose the radial mechanical pressure resulting from varyin as pressures in said chambers upon said rotors, ducts connecting said high pressure zones to said high pressure port, and said low pressure zones to a low pressure re-' gion, whereby the load on said bearings is reduced increasing the total load capacity of said rotors for compression.

MYRON F. m. Farmers A. HILL, 22m.

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