US1923291A - Rotary pump - Google Patents

Description

Aug. 22, 1933. M. E. zlMMr-:RER

ROTARY PUMP Filed Sept. 11 1930 2 Sheets-Sheet 1 YVQJ-z/Ef" 77260@ E. Zimmerer? AU8 22, 1933 4M. E. ZIMMERER 1,923,291

ROTARY PUMP Filed Sept'. 1l, 1930 Sheets-Sheet 2 1) N 53@ Si? m n VEL-#CUF Zark Ef Zimmerer Patented Aug. 22, i933 UNITED STATES PARENT OFFICE Kingston Products Corporation, Kokbknp a Corporation of Indiana Application September l1, 1930 Serial N0. 481,098

1 claim. (ci. 10s-132i This invention relates to an improved rotary pump having particular utility in pumping volatile fluids such as gasoline and more particularly to such a device having a plurality of independent pump compartments.

The various forms of rotary pumps for pumping volatile fluids such as gasoline, do not possess a very high efficiency due to the relatively high amount of electrical energy consumed in their operation for a given volume of fluid delivered. In addition, these pumps employ for the most part contacting moving parts which are subjected to wear, necessitating replacement and hence decreasing the operative life of the pump.

Further when such pumps are constructed with a plurality of independent chambers, it is the custom to form the same in three pieces with partitions integral with the casing separating the various pump compartments. This form of construcy tion necessitates an expensive and tedious metal working operation and moreover because of 'the` number of parts required results in a rather expensive pump. y

In addition due to the volatility and inflammability of gasoline, it is necessary to provide a. liquid type packing for the pump bearing in which the shaft extension connected to the power source is journalled. The usual packingvglands employed frictionally grip the shafts with such tenacity that a material loss of power is experienced in overcoming this frictional force.

I have now provided a rotaryp p havingra plurality of independent pump chambers which overcomes to a great extent the objectionable features pointed out in connection with known forms of rotary pumps.

It is accordingly an object of this invetion to provide a rotary two piece\pump .having a plurality of pump compartments.

It is a further object of thisinvention to provide a. multi-chamber rotary punp-which is compact and simple in construction, has a small initial cost and a materially greater operating efficiency than known pumps. A

A further important object of this invention is to provide a packing gland for the extended end of the pump shaft which provides an effective liquid seal and at the same time exerts a materially 'smaller frictional grip on the shaft than known forms of packing glands.

It is a further important object of this invention to provide an improved lubricating and cooling system for the extended shaft bearing.

Other and lfurther important objects of this \1 4 formed on said plate 7.

invention will become apparent from the following descriptinand appended claim.

Rcferrin'gnow t0 the drawings:

Figure 1 is a vertical sectibnal liew through my improved pump."`4 f Y.

Figure 2\isa section inline II-II of Figure 1.

Figure 3 shows a modified form of rotary pivot for the pu` p rotors-1 Figure 4 iscloses another modified form of such pivot.

Onthe drawings; 71.?

The pump indicatedjny the reference numeral 1 comprises a housingar casing 2 having a section 3 with a-smooth bore 4 therein for receiving the pumpxotors 5. and a plate 'I secured by 70 screws 8 to the section 3 to form a rear closure for the pump b ore 4.

The frontgface 9 of said section 3 is formed with an integral hollow extension 10 providing a bearing 11 for the pump shaft 12. The oppo- 75 site end 13 of said shaft 12 is journalled in a hub Preferably, an antifriction bushing 15 is located between the walls of saiiefhub 14 and the end of said shaft.

That part of the pump shaft 12 located in the 30 bore 4 is formed, in the structure shown, with a pair of abutting cams 16 having their peak points 18 spaced 180 apart about the shaft. Preferably the cams 16 are forged integrally with the shaft 12 but if desired may be made separately 85 and secured to the shaft by keys or pins.

The bore 4 in the pump section 3 is divided into two equal independent pump compartments 19 and 20 by a partition plate 21 located in the pump at the point where the cams 16 abut. 90 Said plate 21 has an aperture 22 therein of suicient diameter to permit the partition to be readily slipped over said cams i6. The diameter of said partition is slightly less than that of the pump bore 4 but if desired it"may be made with 95 such a diameter as to provide apress fit with the walls of said bore. In the first however, the amount of leakage occasioned by the very small clearance between the periphery of said partition and the walls of said bore is so small as to fail to overcome the advantages resuming from the use of the floating partition and accord .lngly this form is to be preferred.

The pump rotors 5 are eccentricaliy mounted 105 in each pump compartment 19 and 20, by means of conventional ball bearings 24 which rather snugly fit over the cams 16. Said ball bearings comprise inner and outer ball races 25 which house the balls 26. The lands 27 of said races 110 are, as shown, of less width than the width of cams 16 which the races encircle.

Each pump rotor 5 has an inner diameter permitting it to be readily slipped over the outer ball races and an outer diameter such that the portion of the rotor periphery in line with the peak of the cam on which it is mounted just clears the Wall of the pump compartment. From this point the space between the rotor periphery of each rotor and the wall of the pump compartment gradually increases in size to a point spaced apart 180 and gradually decreases in size from said latter point back to said first point. There is thus no rubbing action between the pump rotors and the walls of the pump chambers and hence no wear of these parts. There is moreover, no fluid leakage through this clearance as will be later explained. I have found that a 1000 of an inch at the above mentioned point produces very good results.

Each rotor 5 is operatively associated with its pump compartment by means of a rotary pivot 28 which permits a rolling or wiping action of a rotor about the walls of the compartment when the pump shaft 12 is rotated, but prevents rotation of the rotor with said shaft. Said pivots 28 are formed by carefully drilling a cylindrical longitudinally extending opening 29 through the upper wall of the pump section 3 to a depth equal to the depth of the bore 4. Said opening 29 at its underside intersects said bore 4 to provide a narrow communicating passage 29a therebetween. A pair of rotary pivot blocks 30, one for each pump rotor 5, having a cross section like that of opening 29 is then located in said opening 29. Said blocks 30 are spaced from each other to provide a space for the reception in said opening 29 of a tongue 31 on the partition 21 to prevent rotative movement of said partition. Each of said blocks 30 is provided with a slot 32 opening toward the pump bore 4 through said passage 29a. A radial pivot blade 33 is secured to each pump rotor 5 and extends through the passage 29a into the slot 32 in each pivot block 30, wherein it reciprocates as the rotor to which it is fixed wipes around the wall of a pump compartment. The slight tilting action 'necessary in the pivot 28 to permit the wiping or rolling action of the pump rotor is provided by rotation of the pivot block 30 in the opening 29.

Each pivot blade 33 is xedly secured to a pump rotor by forming the lower end of the blade with a headed portion 34 which is located in a recess 35 in the rotor. The metal about said slot is then worked to firmly anchor said base 34 in place. This joint is stronger than a welded or soldered joint and accordingly increases the durability of the pump.

The rotary pivots 28 may take other forms than that shown in Figures 1 and 2. For example, in

rotor having a clearance of approximately vFigure 3 such a pivot is formed by a U-shaped slot 36 opening into the bore 4 and a pivot blade 37 having a chamfered head 38 received in said slot. Said blade 37 reciprocates in said slot as the rotor operates and due to the formation of the head 38 has a slight tilting action therein.

In Figure 4 I have shown another form of pivot comprising a member 39 having a plane base 40 and a curved outer surface 41. The upper portion of said outer surface is secured as at 42 in a groove 43 in the upper wall of the pump casing and reciprocates in a rectangular slot 44 in the rotor 5.

The blades 33, Figures 1 and 2, not only act as pivots for the rotors 5 but also divide the pump chambers 19 and 20 into a suction side 45 and pressure side 46. The suction side 45 of each pump compartment has an inlet port 47 leading thereinto while the pressure side is in communication with an outlet port 48.

Pumps of this nature when used in gasoline stations are operated by an electric motor controlled by the delivery nozzle from the gasoline tank. The release of the delivery nozzle from the tank starts the motor and pump so that in many instances the pump is in operation before the nozzle is opened to deliver the gasoline therefrom. To take care of the fluid pumped into the outlet port in such cases, a relief port 49 is provided between the outlet port 48' and inlet port 47. Said relief port 49 is controlled, adjacent its connection with the inlet port 47 by a valve 50 having a head 50a seating against the end 51 of said relief port. Said valve 50 has a stem 52 operable in a sleeve 53 secured in place by a member 55 threaded in the bore 56. The valve is normally retained against vits seat by a compression spring 57 bearing against the valve head and member 55 and regulated to yield at a predetermined pressure to permit the valve to unseat and open said relief port. A packing gasket 58 secured in place by a nut 59, threaded to the end of member 55 prevents leakage of fluid through said bore 56.

Leakage of fluid through the shaft journal 10 is prevented by means of a packing' gland 60 located in a recess 6l in the outer end of said journal. Said packing gland 60 comprises a hollow resilient cylinder 61a preferably of cork fitting about said shaft 12 and having a groove 62 about the periphery thereof. The ends 63 of said cork cylinder 61a are inwardly inclined and abut against metal rings 64 and 65 which have inclined faces 66 corresponding to the inclination of said ends 63. The inner ring 64 fits against the outer end of the bearing 11 while the outer ring 65 is acted on by a compression spring 69a which bears at its other end against an adjustable cap 67 threaded to the end of said journal 10. Said cap has an aperture 68 therein for the reception of a sleeve 69 which surrounds the shaft 12 and is received at its inner end in a groove in the ring 65. Said sleeve 69 collects fluid which leaks past the packing gland 60.

In this type of gland, the spring 69a maintains a constant pressure against the cork cylinder 61a thereby compressing the same and forcing the material of the packing 60 into tight engagement with the shaft 12. The groove 62 permits greater compression about the periphery of the gland 60 to thereby distort the gland so that the axial pressure caused by threading the cap 67 on the journal 10 exerts a greater radial pressure upon the shaft 12 than would be the case if the gland 60 were not provided with a groove. This gripping engagement does not, as will be readily appreciated, set up a force in opposition to the rotation of the shaft in any degree comparable with that set up with known forms of packing glands.

In this pump I utilize the action of the pump and the fluid operated on by the pump to cool and lubricate the bearing ll. For this purpose a circular groove 70 is provided in the face of the ring 64 seating against the end of the bearing l1 which communicates with a passage 71 leading through the wall of the journal 10 into the suction side of the adjacent pump compartment. Preferably a small metering pin (not shown) is located in the outlet 72 from said passage '11, to regulate the flow of fluid through said passage. As will be apparent the suction of the pump acting through the passage l1 causes fluid to flow from the suction side of the pump compartment adjacent the bearing 11 along the shaft 12 into the groove 'l0 and back to the pump compartment through the passage '71 thereby effectively cooling and lubricating the pump bearing 11.

The width of the rotors 5 is such as to provide a snug but non-contacting nt with the sides of the pump compartments 19 and 20 to thereby prevent' leakage past said side surfaces. The thickness of the rotor walls may of course be varied but for best results they are made as thin as possible consistent with sufficient strength to provide anchorage for the pivot blades 33`- The thinner the walls are made the less will be thel centrifugal force acting on the pump shaft.

The small clearance provided at all times between the periphery oi' the rotors 5 and walls of the pump compartment is sealed by the fluid pumped and hence substantially no leakage takes place from the suction side of the pump compartments to the pressure side thereof. What little leakage does occur is more than offset by the nonwearing structure provided.

I have found that with a pump of this construction, the electrical energy necessary to drive a pump of a given capacity is about 50% less than that required for known pumps of similar capacity. For example, with a pump of the size ordinarily employed at gasoline stations I can pump 15 gallons of gasoline per minute under 18 pounds pressure with a V3 H. P. motor.

While I have disclosed a pump having but two pump compartments it will be understood that as many may be provided as desired, by merely setting olf the spaces to be occupied as pump compartments by the floating partitions disclosed, In this way the number of parts of the pump is not increased and a high saving in initial cost is obtained.

Moreover in my pump the friction between the moving parts is reduced, the peak pressures ironed out and vibration of the parts reduced so that a pump better balanced than known pumps results.

It can thus be appreciated that I have constructed a multi-compartment rotary pump which greatly improves on the forms of such pumps now in use and which is much simpler and can be made at a materially reduced cost.

I claim as my invention:

In a rotary pump including a shaft and having a pressure side and a suction side, a casing for the pump including an axially extending portion having a relatively large packing bore and a relatively small bore providing a bearing for the pump shaft disposed therein, said casing'having a passageway leading from the end of the packing bore to the suction side of the pump, said casing having an internal shoulder at one end of the packing bore, a packing in the packing bore, a metal ring disposed between the packing and said shoulder and having an annular recess disposed toward said shoulder and providing a socket affording communication between the surface of the pump shaft and the eway whereby fluid discharge through the bearing along the shaft will be withdrawn through the passageway by a vacuum to the suction side of the pump.

MARK E. ZILIMERER.

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