US1749121A - Rotary pump - Google Patents

Description

March 4, 11930. L, P. EARL-Ow 1,749,121

. ROTARY PUMP Filed Feb. 16. 1928 2 sheds-snee: 1

/ .Il l l I March 4, 1930. 1 L, P, BARLow 1,749,121

ROTARY PUMP Fl'ed Feb. 16, 1928 2 Sheets-Sheet 2 lzyefzzZo/f l Patented Mar. L 1930 l UNITED STATES LESTER P. IBABLOW, F STANFORD, CONNECTICUT ROTARY PUE? Application filed l'ebruary 18, 1928. Serial No. 254,699.

In my copending application, filed February 14;, 1928, Serial o. 254,222, I have shown, described; and claimed a rotary pump of the positive displacement typein B which rollers are impelled around the 1nside of the pump chamber through the medium of a slotted rotor.

In said pump novel port means are provided whereby the pressures about the rollers are so balanced and regulated that the rollers v retain their contact with the race around the inner surface of the rotor chamber at all times during the operation of the pump, thereby preventing leakage past the rollers fromthe high to the low pressure sides of the pump and also avoiding se'lf destruction of the pump by preventing hammering of the rollers against the race. These ports are in the form of interconnected channels or slots made directly in the end walls of the pump housing at the opposite ends of the rotor and, to secure proper timing in the rotation of the rotor, the slots must be accurately formed inwidth and length. This requires i skilled workmanship in the making of the pum s, and this is not likely to be always obtamed when making the pumps in large numbers on a production basis as required :tor commercial outputs.

To accomplish this result, I locate stationary 'plates in the pump chamber over the slots and cut port holes in these plates, "which port holes registerv with the channels or slots and may be accurately formed and located so as to obtain accurate timing of the pump without careful attention being paid to the making of the channels or slots.

he port holes in the plates may be quickly and accurately made by a punch press operation at a minimum of expense, as the plates may be operatedon in a stack outside of the pump housing and afterward' assembled therein in the required alignment for accurate timing of the pump. This greatly reduces the cost of making the pump, as accurate cutting of the slots or channels' in the end walls of the Dump need not be made, the port holesin the plates defining the beginning and cut-off ends of the channels 5 or slots and` thus making it possible for all pumps made tohave accurate timing even lthough produced in large numbers on a production basis.

Another object of my invention is to dowel or otherwise x the plates in the pump at the opposite ends of the rotor and thus insure the .positioning of the plates in each pump in proper alignment for accurate timing on both sides of the pump.

The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawings- Fig. 1 is a side View of a pump constructed in accordance with my invention;

Fig. 2 a front `View of the pump;

Fig. 3 is a View looking into the pump, with the cover plate removed;

Fig. 4 is a vertical sectional view taken on line 4-4 of Fig. 1, with the rotor and rollers omitted to show one of the interior port plates;

Fig. 5 is a similar View with the port plate removed to show the port arrangement behind the same;

Fig. 6 is a face view of a port plate;

Fig. 7 is a longitudinal vertical sectional View through the pump with all parts in place;

Fig. 8 is a vertical sectional View taken on line 8f-8 of Fig. 4; and

Fig. 9 is a vertical sectional view through the cover and its attached port plate.

In the drawings, 1 indicates the housing of the pump provi-ding a chamber in which is tightly fitted a race-ring 2 of metal of the desired hardness. The housing is closed at one end by a cover-plate 3 and at the opposite end by an end Wall 4 which is made integral wlth the housing. Thecover plate 3 is secured to the housing by fastening screws, as shown.

Located in the ring 2 is a cylindric rotor 5 keyed or otherwise fixed to a shaft 6 which extends through the end walls 3, 4 of the housing and is journaled therein, as shown` in Fig. 7. The rotor 5 is smaller in diameter than the inside of the ring and is eccentrically mounted therein so that the peripheral surface of the rotor may be brought closeto the inner surface of the ring on one side'of A operation of the pump.

the rotor while providing a relatively wide gapor clearance space between the rotor and the ring on the opposite side of the rotor, as shownl in Fig. 3. The rotor 5 is provided with a multiplicity of radial slots 7 equally spaced about the circumference of the rotor and opening through the opposite ends of the rotor and also through the outer peripheral surface thereof. Rollers 8, 8, which are slightly smaller in diameter than the width of the slots; are located therein and run against the inner surface ofthe ring 2 in the With the rollers lesser in width` .than the slots, the rollers are laterally movable the slots and thus, while on the discharge side of the ppJnp, may be forced by the high pressure iuid against the rear sides of the slots to provide passages to the bottoms of the slots about the front or advancing lsides' of the rollers so that the high pressure fiuid from the periphery of the rotor may enter the slots beneath the rollers to hold them in sealing contact with the inner surface ofthe `rotor chamber on the discharge side of the pump.

The intakeand discharge 9, 10 of the pump extend through the body of the housing 1 on opposite sides of the rotor and open, respectively, into chambers 11, 12 provided in the housing on the outerfside of the ring 2, as shown in Fig'. 4. These chambers 11 12 are wider than the ring 2, as shown in Fig. 7, so that the fluid medium handled by the pump may flow about the sides of the ring in pass-I ing throughA the pump.

The porting means heretofore mentioned comprises a set of inner and outer interconnected arcuate channels in each end wall 3,

i v 4 at the intake and discharge sides 9, 10, re-

spectively,lof the pump. The outer channels 13, 14 in the end walls 3, 4 are arranged inside of the ring2and have communication around the sides of the ring with their respective chambers 11, 12, the channels continuing outward beyond the sides of the ring for this purpose, as shown in Fig. 5. The inner ychannels 15,16 in the end walls are close to the shaft. 6 andhave communication with their respective Iouter channels 13, -14 by passageways 17 lfrespectively.` The lchannels 13 are considerably longer than the chamber 11 and extend to within close proximity to where the rotor and ring are the closest together, as at A in-Fig. 3; so as to afford the longest Epossible'period ofjfeeding the low pressure side of the pump from the inlet 9. The opposite 'ends of the channels 13 and chamber 11 register at the cut-oif between the high and low pressure sides of the pump. The channels 14 on the outlet side of the pump extend relatively close to the closest point A 'between the rotor and the ring 2 so as to reduce .to the minimum the tendency to hydraulic and permit the minimum amount of liquids to be displaced past the rollers as they approach this high point. This displaced fluid finds outlet around the front side of the rollers to the bottoms of the slots 7 and into the inner channels 16, from'which it may flow into the -discharge chamber 12 and` relieve the pressure at the rollers as they advance to this high point of the rotor. lWhen Working with non-collapsible liquids, such as oil o`r water, the ring 2 would be scored and distorted-if these pressures could not be relieved even though the film of liquid would,

not be more than .001 of an inch thick.

' The inner channels 16 of thehigh pressure set extend to close proximity to the cut-off at the intake side of the pump so that said inner channels will communicate with the bottom of the slot of the nextadvancing roller imme- -diately that such roller passes the cut-off, and thus pressure from the high pressure side of the pump acts on the under side of the roller so that it' will be maintained against the ring 2 and not be driven from the race and into the slot by theA high pressure ofthe discharge side with. which the roller comes in contact on passing the-cut-ofi. These inner channels 16 extend far enough aroundv the.

pump so as to maintain a pressure' on the under sides of the rollers from this cut-off to the beginning of the intake as established by the outer channels 13 on the low pressure side vof the pump. In this Way the pressures on lthe cut-ofi' ends of the outer channels 14, the

relief of pressure on the driving sides of the rollers is not only secured, as heretofore mentioned, but the spaces in the bottoms 40f the slots under the rollers as they tend to increase by the rollers advancing toward the opening of the' inlet side ofthe pump are supplied with pressure from the inner channels 16, and thus the rollers will be maintained against the inner surface of the race-ring 2 without depending on any centrifugal forces set up on therotation of the rotor until the roller slot passes the cut-off end of the inner channels 16. When this happens, the bottom of the slot 7 of the advancing roller is brought into communication with the' inner channels 15 on the low pressure side of the pump, and

outlet side of the pump by registration with.

the inner channels 16, as heretofore described. The port plates heretofore mentioned are two in number and are indicated by'19, 19,y

respectively. These plates are circular in form, as shown in Fig. 6, and are fitted in the housing 1 on opposite sldes of the race-ring 2, as shown in F ig. 7. The plates extend to the outer^edges of the ring 2 so as to have a snug fit in thef housing 1 and are fixed against rotation therein. in any preferred way, as by dowel pins 20, 2O which extend into holes 21, 21y drilled or otherwise formed in the cover 3,. and end wall 4, respectively, as shown in Figs. 8 and 9. The 'holes for the dowels 20 in both the plates 19 and end walls 3, 4 are diametrically disposed and have the same positions in all the parts so that the plates may be made exactly alike and be used interchangeably at the opposite ends of the rotor 5. This reduces the cost of making the as sembly, as the makingof right and left-hand plates-is avoided. The dowels are so located -as to be covered by the ring 2 and thus are prevented bythe ring from coming out of place. With the plates 19, 19 at the opposite ends of the rotor 5, the plates extend over the interconnected channels 13, 14 in the end walls 3, 4 and close said channelsto the rotor` except for the sets of ports which are provided in the plates for said channels. As shown in Figs. 4 and 6, each plate 19 has a set of outer ports 22, 23 and a set of inner ports 24, 25. The ports of each set are in the form of 1ndividual disconnected holes punched or otherwise formed lthrough the plate and spaced apart circumferentlally aboutthe same in their proper positions. `The port holes 22, 23 of the outer set are located near the outer periphery of the plate and extend inside .of the race-ring 2 to approximately the depth of the outer channels 13, 14 and register respec tively therewith, The port holes 24, 25 ot the inner set are arranged about the hole in the center of the plate where the shaft 6 extends through it, and these ports are positioned to register respectively with the inner channels 15, 16. The port holes of both sets are multiple in number and are made large enough to allow for a free and rapid iow of fluid therethrough and thus have no restrictive eie'ct on the continuous and constant flow of the pump on either its intake or discharge sides.

The outermost end edges of the port holes at 'the opposite ends of each group of ports 22 to 25 define the beginning and cut-off respectively for the respective interconnected channels with which said portholes register.

' In this way the timing of the pump in the rotation of the rotor 5 maybe accurately devtermined and set without accurately forming the channels to bring their ends in accurate register with where the intake and discharge `sides of the pump must begin and cut ofi.

` With the port holes in the plates 19,`the ends of the channels may vary slightly on one side or the other with the edges of the holes without aifecting the accurate timing of the pumpv lVith the timing determined by the port holes in the plates 19, the pumps when made in large numbers on a production basis Jfor commercial outputs are easierv andv cheaper to manufacture than when the plates are not employed, as then the channels 13 to 16 must be accurately made to secure the timing desired. While pumps so made are just as eficient asthose provided with the port plates herein described, yet from a production standpoint where expense of manufact/ure is an important tactor'the plates will reduce the production costs.

The spacing between the opposed port holes 22, 23 in the plates 19 at the high point A of the -rotor 5 is slightly greater than the width of a rotor slot 7 so that the high pressure side of the pump can not leak to its low pressure side through a rotor slot when the latter is central between saidport holes as the rotor slot passes between them. The edges of the port holes in each group at the ends defining the. beginning and cut off, respectively, of the low and high pressure sides of the pump are made straight so that these points will be sharply deiined and not delay the timing of the rotor action in passing these ports.

The pump of my invention ishighly eiiicient due to the fact that the moving parts Jand the chamber in which they are located are in posit/ive contact and remain in contact over a long life of the pump.V This contact can be 'maintained regardless ofv the amount of wear that may be developed either in thel chamber or on thel rollers or in the rotor, as v the rollers are always free to automatically move out tothe point of wear. The pump can operate either at exceedingly slow speed and still pump at pressure, or can operate at extremelyhigh speed with the same eiiiciency, thus making it acceptable when directly driven by a variable speed machine, such as internal combustion engines in automobiles, etc. Furthermore, the pump with its novel porting arrangement makes possible the economical production of pumps on a production basis with accurate timing at all Irotary speeds without Vibration and with the minimum amount of noise. Moreover, the pump func` tions Without the use of valves, the slotsl 7 and rotor 5 functioning as cut-n and cut-out at the ends of the various ports in properly timed relation with the action of the pump. Also the pump has the very minimum of moving parts and these parts are extremely rugged and have exceedingly long life. This makespossible a very light weight pumplof large capacity and small size where the min- .imum of space so demands. It is particularely applicable for use as .water, oil, and fuell pumps on aeroplanes, where minimum weight, size, and high capacity are desired.

The details of ystructure and arrangement of parts may be variouslj7` changed and modified without departing from the spirit and scope of my invention.

I claim as my invention: 1. A rotary pump, comprising a housing having a rotor chamber with a raceway therein, said housing having intake and discharge openings for said chamber, a'rotor in said chamber and having radiall slots opening through one end of the rotor, rollers working in said slots for displacing fluid through said chamber, inner and outer interconnected arcuate channels formed in the housing at the open ends of said slots, the outer-channels constantly connecting with. the intake and discharge openings, respectively, and serving the outer end portions of the slots, and the inner channels serving the bottoms of the slots beneath the rollers, and a plate in the housing` over said channels and fitting against the adjacent side of said raceway, said plate having inner and outer sets of port holes eX- tending therethrough and in register with the inner and outer channels, respectively.

2. A rotary pump, comprising a housing having a rotor chamber with a raceway therein, said housing having intake and discharge openings for said chamber, a rotor in said chamber and having radial slots opening through the periphery and the opposite ends -of therotor, rollers working in said slots for displacing fluid through said chamber, inner and outer interconnected arcuate channels formed in the housing atthe opposite ends of the rotor, the outer channels connecting constantly with the intake and discharge openings, respectively, and serving .the peripheral portion of the rotor, and the inner channels serving the bottoms of the slots beneath the rollers, and plates in the housing over the channels and fitting against the opposite sides of said raceway, said plates having inner and outer sets of 4port holes extending therethrough and in register with the inner and outer channels, respectively.

3. A rotary pump, comprising a housing, a race ring therein, a rotor eccentrically mounted in said ring and provided with radial'slots opening through the periphery and the opposite ends of the rotor, rollers in said slots and working against the inner surface ofsaid ring, said housing having intake and discharge passages including inner and out-- er interconnected channels formed in the housing at the opposite -ends of the rotor for the inner and outer portions of said slots, plates in the housing on opposite sides of the ring over said channels and havlng port holes in register with the respective inner and outer portions thereof, and dowels tting the plates in the housing with the dowels overlapped by the adjacent edges of the ringT 4. A rotary pump, comprising a housing having a chamber, a rotor eccentricallymountedftherein and provided with radial slots opening 'through an end of thev rotor, rollers working in said slots, said housing having intake and discharge passages including inner and outer interconnected channels formed therein opposite the open ends of the.

slots for the inner and outer portions thereof, y

and a plate fitted in the chamber over said channels and having inner and outer rows of port holes in register with the inner and outer portions of said channels respectively, the port holes at the ends of the channels having straight edges.

5. A rotary pump, comprising a housing having wall sections closing the opposite sides thereof, one of said Wall sections having a `fixed connection with the housing and the other having a detachable connection there with, a race-way in the housing between said wall sections, a rotor eccentrically mounted within said race-way and having radial slots opening through the periphery and the opposite ends of the rotor, rollers in said slots and working against said race-way, inner and outer interconnected channels in lsaid wall sectlons opposite the open ends of said slots, plates in the housing between the wall sections and the race-way and overlapping the side edges of the latter, said plates having port holes in register with the respective inner and outer portions of said channels, and intake and vdischarge passages in the housing and connected with 'the outer channels.

6. A rotary pump, comprising a housing having a rotor chamber with a race Way therein,fsaid housing having intake and discharge passages for said chamber at one side thereof, a rotor in said chamber and having radial slots opening through the end of the rotor adjacent to said passages, roller pistons in said slots for displacing fluid through the chamber, said pistons being lesser in width than the slots so as to be laterally movthe periphery of the rotor to the portions of the slots beneath the pistons on the advanclng sides of the same and a plate in said housing over said passages and fitting against the adjacent side of the raceway, said plate Aable therein to provide passages leading .from y having ports connecting the chamber with tor, roller pistons in said slots for displacing the fluid through the chamber, said pistons being lesser in Width than the slots so so to be laterally movable therein to provide passages leading vfrom the periphery of the rotor to the portions of the slots be-v neath the pistons on the advancing sides of the same, and plates in the housing over said passages and fitting against the opposite sides of said race way, said plates having ports connecting the chamber with said passa es and defining the beginning and the cuto of communication ofthe chamber with said passages for controlling the timing of the pump.

8. A rotary pump, comprising a housing having a rotor chamber with a race v,way therein, said housing having intake and discharge passages for the chamber, .a rtor ecceutrically mounted in said chamber and having radial slots, roller pistons in said slots and working-against said race Way for displacing iuid throughsaid chamber, said pistons being lesser in width than the slots so as to be laterally movable therein to provide passages leading from the periphery of the rotor to the portions of the slots beneath thev pistons on the advancing sides of the same, and means in the housin between the rotor and said passages for de ning the beginning and the cut-off' of communication of the chamber with said passages for controlling the timing of the pump, said meansA being positioned in the housing by said race way.

9. A rotary pump, comprising a housing having a rotor chamber and intake and discharge passages therefor, a rotor in said -chamber and having radial slots, pistons loosely working in said slots for displacing fluid through said chamber, said passages serving the inner and outer portions of the slots so that the pressure of the passing iiuid through the chamber will not unseat the pistons from continuous contact with the inner surface of said chamber, and means in the housingbetween the rotor and said passages for defining the beginning and the cutoii' of communication of thechamber with said passages for controlling the timing of the pump.

v10. A rotary pump, comprising a housing having a rotor chamber and intake and discharge passages therefor,a rotor in said chamber and having radial slots, pistons working in said slots for displacing Huid4 g through said chamber, said passages having channels opposite one end of the rotor and serving the inner and outer portions of the slots so as to maintain the pistons by iuid pressure in continuous contact with the inner surface of said chamber during the operation of the pump, and means in the housing over V said channels for dening the be innin and the cut-olf of communication o the ber with said passages for controlling the timing lof the pump.

11. A rotary pump, comprising a housing having intake and discharge openin s, a race-ring fitted in said housing, plates tted in the housing on opposite sides of the ring and forming therewith a rotor chamber, a rotor eccentrically mounted in said chamber between said plates, said rotor having radial slots opening through the periphery of the rotor and through the ends of the same, roller pistons mounted in said slots and working against the inner surface of said ring with the pistons no longer than the length of the rotor, said pistons rbeing lesser in width than the slots so as to be laterally movable therein to provide passages leading from the periphery of the rotor to the portions of the slots beneath the pistons on the advancing sides of the same, said ring spacing the plates from the ends of the rotor to provide a running clearance between them, channels in the housing on the outer sides of the plates and connected with the intake and the discharge openings, respectively, said plates havin ports to. register with said channels, sai ports defining the beginning and the cut-off of communication of the chamber with said channels for controlling the timing of the Pump- In testimony whereof I affix my si LESTER P. BA

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