US666869A - End-thrust counterbalance for centrifugal pumps and shafting. - Google Patents

Description

Patented lan. 29, |690I.

F. H. JACKSON.

(Application med sept. 7,1699.)

END THRUST CUUNTERBALANCE FOR CENTBIFUGAL PUMPS AND SHAFTING.

(No Modal.)

UNITED STATES PATENT OFFICE.

FRANK H. JACKSON, OF SAN FRANCISCO, CALIFORNIA.

END-THRUST COUNTERBALANCE FOR CENTRIFUGAL PUMPS AND SHAFTING.

SPECIFICATION forming part of Letters Patent No. 666,869, dated January 29, 1901.

Application filed September '7, 1899. Serial No. 729.679. (No model.)

To all whom it may concern:

Be it known that I, FRANK H. JACKSON, a citizen of the United States, residing in the city and county of San Francisco, State of California, have invented an Improvement in End-Thrust Counterbalances for Centrifugal Pumps and Shafting; and I hereby declare the following 1o be a full, clear, and exactdescription of the same. a

My invention relates to end-thrust coun.- terbalances for centrifugal pumps and shafting; and it consists of the parts and the constructions and combinations of part-s hereinafter described and claimed.

Figure lis a sectional View showing the runner revoluble in a horizontal plane. Fig. 2 shows the runner upon a horizontal shaft and running in a vertical plane.

It is well understood by those familiar with centrifugal pumps that the discharge pressure between the runner andthe case is never equal to the total discharge pressure in the involute of the case or the discharge-pipe of the pump and that these variations will cause an unequal pressure on the two sides of the runner, which has a tendency to force it in one direction or the other if not held in place by collars. This variation and end thrust also occurs either from the weight of the shaft and attached parts when running vertically or from action of the propelling mechanism or the unequal hydraulic pressure caused by variations of the suction on one side and the variations in the pressure from the discharge.

It is the object of my invention to automatically regulate these pressures and so counterbalance the runner or impeller that it will always remain approximately central within the case without the aid of collars or other mechanical support.

In my improvement the runner or impeller is constructed with running-joints, the joint upon the opposite side from the suction-entrance having approximately about the same diameter as that of the suction-entrance, this being varied, however, to produce an equilibrium between the counter-thrusts. In other Words, a flange G projects from one side of the runner into the suction-chamber (above the runner in Fig. l) and another [lange H projects below the runner. Both of these flanges turn in corresponding sleeves or flanges, the lower one being lettered H in Fig. l, and said flanges are slidable up or down as the runner rises or sinks. The discharge pressure reaches the chamber Within the liange opposite to the suction side of the runner through the running-joint of this flange, and when this pressure exceeds that of the suction side a slight movement of the wheel toward that direction partly opens a central passage, which discharges the surplus pressure by connecting this chamber directly with the suction.

The main casing C is volute in form having the peripheral discharge space, as shown. Within the central portion of the casing is the runner or impeller D, so called, which is fixed upon the driving-shaft M, suitably journaled and extending into the case, as shown. Power is applied to this shaft in any suitable or desired manner to give motion to the runner. This runner is of the inclosed form and consists of disks or sides having hollow arms or vanes extending from the central portion to the periphery. When power is applied to rotate this runner, the pump being properly primed, the centrifugal action will draw water through the suction or inlet pipes E and through the inlet-openings F in the runner, discharging it outwardly into the peripheral discharge-passage C.

The impeller has a flange G extending into the suction-passage and forming a runningjoint therein. Upon the opposite side of the impeller is a projecting flange or ring H,which enters into and forms a running-joint with a corresponding flange H upon the side of the case opposite to the suction. These flanges G and H are movable in their respective chambers, and they form the dividing-line between the suction and discharge pressures. Openings I are made through the disk of the impeller opposite to the suction, and a central opening I connects this space With the space K,which is formed Within the running-flanges H H'.

J is a plug or projection central within the 4chamber K and of such diameter that it fits the passage I when the impeller is forced away from the suction-inlet, and when the impeller moves toward the suction -inlet it will be withdrawn from this plug or projection, so as to leave an open passage between the cham- IOO ber K through the openings I and I to the suction-inlet.

Vhen the machine is in operation, the pressure due tothe discharge surrounding the impeller or runner will be admitted through the running-joint between the flanges H a-nd H', and thus produce a pressure in the chamber K, which in the case of the vertical arrangement of the pump serves to support the weight of the running parts and in any arrangement to resist any thrust in that direction. Whenever the pressure within this chamber is greater than t-he pressure from the opposite side, the runner will be moved a short distance until the passage I' is opened by reason of the runner having moved away from the projection .I until it passes more water than can pass the running-joint H and H', thus allowing the surplus pressure to pass directly through the openings I into the suction-inlet of the pump. XVhencver the pressure from the opposite or suction side is greater than that from the discharge side, the runner will move slightly until the passage I fits over the projection J, when the pressure from' the discharge entering the chamber K will again act to resist further movement in this direction. In this manner the differential of pressure upon one side or the other acts constantly to balance the runner and retain it in its proper central position where the unequal balance is caused by hydraulic pressure, the gravity of the moving parts, or the drivingT force, the runner being held in equilibrium approximately in the center of the pum p-case without the use of thrust collars or bearings, and the result is the same whether the shaft is vertical, horizontal, or whether the pumps are simple or compounded. It will be obvious that this balancing may be effected by any available hydraulic pressure upon one side and any suitable discharge or relief upon the opposite side and may be applied to revolving shafts other than those of centrifugal pumps, such as the propeller-shaft of a steamship, the vertical shaft in flour-mills, or water-wheels, and any other power plants where the hydraulic pressure may be produced by a pump installed simply for the purpose of hydraulic pressure.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a centrifugal pump, the combination of a case, an inclosed runner or impeller mounted upon a shaft and revoluble Within the case, a suction-inlet passage concentric with the shaft upon one side of the case, an annular flange projecting from the impeller into saidinletfortningarunning-jointtherein, a corresponding flange projecting from the opposite side of the runner, an annular flange projecting from the casing forming a chamber into which the said tlange of the runner extends and is revoluble, a passage connecting said chamber with the suction-inlet and a central plug or piston controlling said passage.

2. In a centrifugal pump, the combination of an exterior casing, a runner mounted upon a shaft and revoluble within the casing, said runner having closed sides and radial van es or passages, a suction-inlet connecting with the casing and the interior of the runner around the shaft upon one side, passages through the opposite side of the runner, a chamber formed in the opposite side of the case, annular flanges formed upon opposite sides of the runner, one forming a runningjoint in the suction-inlet and the other a similar joint. in the chamber upon the opposite side,said chambcrrcceiving pressure from the discharge of the pump, a passage made centrally through the hack of the runner and connecting the suction-inlet directly with the rear chamber, and a plug or piston over which said passage tits and is movable to close or open communication between the chamber and the suctioninlet.

3. The combination in a centrifugal pump of an automatic balancing device consisting of annular [langes projecting from the opposite sides of the inclosed runner, one of said flanges forming a running-joint within the relief-passage, and the otherl extending into and forming a similar joint in a chamber formed upon the opposite side of the casing, passages connecting the discharge and the interior of the runner with said chamber and a plug or piston with relation to which the runner is movable in the line of its axis so as to close or open said passages.

In witness whereof I have hereunto set my hand.

FRANK H. JACKSON.

Witnesses:

J oHN W. NYE, LEE D. CRAIG.

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