US1595636A - Horizontal pump - Google Patents

Description

Aug. 10 1926'l Patented Aug. 10, 1,925 i,

UNITED STATES 1,595,636 PATENT oFF-TCE.

MICHAEL E. WALTEIRS AND ARTHUR R. W-EIS, 0F HUNTINGTON PARK, CALIFORNIA,

ASSIGNORS TO PACIFIC PUMP WORKS, 0F

CORPORATION OF CALIFORNIA.

`HUNTINGTON PARK, CALIFORNIA, A

HORIZONTAL PUMP. i

Application mea January 13,1925.' serial No. 2,153.

This invention relates to horizontal centrifugal pumps, and it relates particularly to two-stage pumps of this type.

' FThe present form of two' stage centrifugal pump generally has a first stage impeller chamber and a second stage impeller chamber, in which first stalge and second stage impellers are respectively positioned, these im,- pellers being secured to a shaft which is adapted for driving through suitable means. A suction passage connects with aconcentric entrance of the first stage impeller. A fluid such as water enters the suction passage and .flows into the impeller entrance. The fluid is engaged by blades of the first stage im.- peller and is thrown to the periphery of the impeller due to centrifugal force. The Huid leaves the periphery of the first stage impeller, passing into the first stage impeller chamber and from thence it Hows into' .a crossover passage which connects between the peripheryof the first stage impeller chamber and a concentric mouth of the second stage impeller chamber. VVaterenters the mouth of the second stage impeller and is rotated by blades thereof, the water being thrown outward by centrifugal force. The axial pressure of the water against the impellers of the pum-p tend to move these. vimpellers axially along the shaft` on which theyrare carried, and it is, therefore, neces,- 'sary to provide means for securing them against axial movement, such means as lock nuts being customary arrangements employed .for this purpose. The cross over passage connecting between lthe first and secondl stage impeller chambers is generally provided in an eXtra casting which is bolted to the main body of the pump.

It is anobject of our invention to provide a horizontal centrifugal pump of the type mentioned-in which the pressure against the impellers thereof is substantially in equilibrium. We accomplish'this bv providing first and second stage impellers which are in the form of an integral rotor. 'Water from an inlet passage of the pump enters the first stage impeller, and water from a cross over of the pump enters the second stage impeller in such a manner that thewater pressure opposing axial movement in the integral rotor is counteracted., This particular construction tends to neutralize the tendency of movement in .the rotor.' The centrifugal pump is constructed., however, so that there will be a slight leakage between the impelf to remain in a proper positionagainst an.

abutment so located thatl the impellers will be `properly positioned in their impeller chambers and so that the rotor will not engage the body of the pump.

It is another object of our invention to provide a centrifugal pump of this character in which the cross over passage which 'extends between the first and second stage' impeller chambers is formed in the main body of the pump. This eliminates an eXtrav casting as was previously necessary. It reduces the cost of the pump, makes the'pump more compact, and renders it of a better design.

, Other objects and advantagesb of this invention will appear in the following specification.

With reference to the two sheets of drawl ings which are for illustrative purposes onlv,

. Fig. 1 is a vertical longitudinal cross section of a two-stage horizontal centrifugal pump taken substantially on the line 1-1 of Fig. 2.

Fig. 2 is an end View of the pump shown in Fig. 1 taken as indicated by the arrow 2 of Fig. 1.`

Fig. 3 is va vertical cross section taken l through a first stage impeller chamber of the pump, this section being taken substantially on the line 3 3 of Fig. 1.v

` Fig. 4 vis a vertical cross section taken through a second stage impr-ller chamber of theY pump, this view beingtaken substan tially on the line 4 4 of Fig. 1. y

The form of our invention shown in the drawings provides a base 11 and a cap 12 which cooperate to provide a main body 13. yThese members 11 and 12 are provided with flanges 15 and 16, respectively, throughL which bolts 17 ext-end 'in a manner to secure these members together. A first/stage impeller chamber '18,and a second stage impeller chamber 19 are provided in the body eoA sides of the chambers 18 and 19. An arm.

27 at the left side of the .body 13 carries a bearing box 28, in which ball bearings 29 supporting the left end of the shaft 23 is secured. An arm 31 provided at the right end of the body 13 carries a bearing box 32 which supports a bearing 33, this bearing 33' rotatably support-ing the right end of the shaft 23. This construction is substantially the same as the bearin construction at the left hand end of the ody 13. The right hand end of the shaft 23 extends entirely through the box 32 as shown, and has a fiexible connection flange 34 secured at the end thereof, thereby providing a means through which the shaft 23 may ber driven.

A rotor 36 is carried by the shaft 23; `this rotor has a hub portion 37 which surrounds the shaft 23 and which is secured thereto i by means of a gib head key 38 having a gib head 38EL forming an abutment against which the leftward end'of the hub 37 engages.

This hub 37 extends through the opening 21 in the central Wall 20 and extends into the chambers 18 and 19. A first stage impeller 39 is` formed integral with the hub 37 and is positioned in thefirst stage impeller chamber 18, and a second stage irnpeller 4() isformed integral with the hub 38 and is positioned in the second stage impeller chamber 19 as shown clearly in, Fig. 1 of the drawings. rThe first stage impeller is rovided in the .form of a radial wall 42 which extends from the hub 37; a plurality of blades 43; and a radial Wall 44, the radial Wall r44 being spaced away from the wall 42 bythe plurality of blades 43. An annular projection 45 extends concentrically from the radial wall 44 into a suction mouth 46 of the body 13.

The second stage limpeller 40 includes a radial IWall 48 .which extends from the hub 37 ,Y and a radial `wall 49. The radial wall y49 is spaced away from the radial wall 48 by means of a plurality of bladesI 50. An annular projection 51 extends concentrically from the radial wall 49 into a `cross over mouth 53 of the body 13. The annular projection 45 provides a concentric entrance 54 for the first stage impeller 39 with the suction mouth 46 of the body 13.

A cross over passage 60 is formed in the body 13.

chamber 18 and the concentric cross over mouth 53 of the body 13. As is evident from the drawings, this cross over passage 60 extends from the first stage impeller chamber 18 around the second stage impeller chamber 19 to the cross over mouth 53. An exhaust passage 63 connects with the periphery of the second stage impeller cha-n1- ber 19 as clearly shown in Fig. 4 of the drawings. v

Water or any other fluid enters the suction passage 58 through suitable means such as piping 64 whichis connected to the body 13 as shown in Fig. 2. This water passes through the suction passage 58 and enters the concentric entrance 54 of the first stage impeller 39. The shaft 23 and rotor 38 at this time are rotatetd at a high rate of speed. By reason of' engagement of the water by the blades 43, the water is given rotation. Centrifugal force, due to this rotation, throws the water outward through the impeller 48 at a high velocity into the periphery of the first stage impeller chamber 18. The water passes from the periphery of the first stage impeller chamber 18 into the cross over passage 60. From the cross over passage' 60, the water passes into the concentric entrance 55 of the second stage impeller 40. The water is engaged by blades 50 of this impeller and is caused to rotate. Centrifugal force throwsthe Water outward from the impeller at a high velocity into the second stage impeller chamber 19. The water Hows around the periphery of the This cross over passage 60 as 1 shown in Figs. 1, 3 and4 connects between the periphery of they first stage impeller second stage impeller chamber 19, and passes therefrom into the exhaust passage 63 and is carried therefrom by Suitable means such as a pipe 66 which is connectedto the body 13 as shown in Fig. 4 of the drawings.

By inspection of Fig." l it is evident that the Water entrances 54 and55 of the first and second stage impellers 39 and 40 are extended in opposite or opposing direc; tions. It is likewise evident that water entering these entrances 54 and 55 passes thereinto in opposing directions. vTater pressure in the first stage impeller cham-` ber 18. produces a tendency for the first stageimpeller 39' to move in a leftward direction, and the Water pressure in the v second stage impeller 19 produces a tendency forthe second stage impeller 40 to move in a rightward direction; that is, the tendency for the impellers 39 and 4() is to moveI in opposite directions. 2l in the central Wall 2O` is made slightly larger than that portion of the hub 37 which extends therethrough. This is The opening tentionally provided thusly so that there ,w1ll be a slight leakage from the high pressure chamber 192into the low pressure chamber 18. If there were no leakage be? tween these chambers, the tendency of movement of the impellers 39 and 40 in opposite directions would be equalized, this being due to the well known thrust ratio for opposed double stage. centrifugal pumps of this general type, in which the discharge pressure of the first stage less the .intake pressure thereof denotes thrust-towards the intake end of the pump and in which the discharge pressure of the second stage less the intake pressure thereof denotes thrust in the opposite direction. If the pump herein illustrated were not provided with interchamber leaka e the thrust e nation would be P18-P54: -1355, in w ich P denotes pressure, and in which the numerals are reference characters in Fig. 1 and used in the equation to designate the respective intakes and discharge .portions of the two stages. However, as it is not desired to have the rotor in equilibrium, the interchamber leakage is provided to lower P19, thereby decreasing the 'right thrust'of the high, pressure stagev and to increase P18, thereby increasingfthe left thrust of the low pressure stage, with a resulting predominant left thrust for the complete pump. There is then a very slight tendency for the rotor' 36 to move in a leftward direction. The leftward end. of the hub 37 as previously mentioned, engages the gib head 38a of the key 38 which prevents a movement of the rotor 36; however, when the rotoris being rotated, the rotor y36 Valwayspressurably engages with the gib head.38. This is extremely desirable owing to the .fact that it retains the rotor 36 in a proper`working position.

is retained in the position shown 1n ther The rotor drawings so that the impellers arecentralized in their impeller chambers and so that the rotor is not engaged with the body 11 of the pump at any point. If the rotor were exactly in equilibrium, there would be a freedom 'thereof relative to the shaft, and the rotor would remain not in a certain position, but in any position into which it is forced during the starting of the pump. The rotor might at .this time engage with the body. of the pump, causing in my invention. The shaft 23 is reversible and makes the pump convertible from a right hand drive into a-left hand drive.

pump. This is possible because .of the fact that the shaft is uniformly cylindrical, and there are no formations which would interfere if the shaft 23 were reversed.

It is -a feature of the invention to provide a novel arrangementwhich includes the cross over passage 63. Our invention is so designed that it is possible for us to form the cross over passage in Ithe main body 13 of the pump. We accomplish this by reason of the compactness of design of our invention. By being able to form the cross over passage 60 within thebody 13, it is possible for us to produce an "eiicient pump at a cheaper cost than pumps of this type which require an extra casting which is bolted to the main casting for the cross over` of the pump. The elimination of anl extra casting also contributes to superiority in design, making a pump which is of better appearance and more compact than othv er pumps. l

Although we have described and delineated our invention in the form of a twostage centrifugal pump, we wish' it to be clearly understood that we may employ our invention in pumps having more 4stages and other designs without departing ,from thespirit and scope of this invention. V Ve claim as our invention: p 1. In a centrifugal pump, the combina-- tion off: a housing forming a first stage im- 'peller chamber and an adjacent second stage impeller chamber; a drive shaft extendine' through said chambers; a rotor carried by andV slidable on said shaft, said rotor comprising first andsecond stage impellers positioned respectively in said first and second stage chambers; and a key rotatably connectmg said rotor to said shaft and formed to' provide an abutment limiting thel slidingof the rotor on the shaft in oneY direction.

2./In ra centrifugal pump, the combination of z' a housing forming a first stage impeller chamber and Aan adjacent second 'stage' impeller chamber separated by a wall having an axial opening; a drive shaft extending through said ,chambers and sald opening; a rotorcarried by and slidable on said shaft, said rotor comprising a. hub surrounding the shaft and extending through said opening and irst'and second stage impellersl extending from said hub into the res pectivev chambers; and a key rotatably connecting said rotor vto said shaft and formed to provide an abutment to be en.

gaged by one end of said hub to limit-the sliding of the rotor on thev Shaft in one direction.

3. In a centrifugal pump, the combina-y tion of: a housing forming a low pressure impeller chamber having a suction inlet, a high pressure impeller chamber having a discharge outlet, a cross-over passage connecting the low pressure chamber outlet with the high pressure chamber inlet, and a wall separating said chambersand having an axial opening; a drive shaft extending through said chambers and said axial opening; a rotor carried by and slidable on said shaft, said rotor comprising a hub surrounding the shaft and 'extending through said opening and low and high pressure impellers extending from said hub into the respective chambers; and a key rotatably connecting said rotor to the shaft and formed to provide an abutment to be engaged by one end of said hub to limit the sliding of the rotor on the shaft in one direction, said opening being of a diameter larger than said hub to permit constant leakage from the high to thelow pressure chambers to insure an axial thrust suiiicient to maintain the rotor hub in engagement with said abutment.

4. In a centrifugal pump.` the combination 0f: walls forming an impeller chanber having an inlet and `an outlet passage; a shaft extending concentrically through said impeller chamber; a rotor carried by said shaft in said impeller chamber; and a key rotatabl connecting said rotor with said shaft an having a head forming a stop, said rotor being slidable on said shaft Iand held against said head `of said key by v,the pressure of a fluid passing into said impeller chamber through said inlet passage.

5'. In a centrifugal pump, the combination of a housing forming a low pressure chamber and an adjacent high pressure chamber; a drive shaft extending through said chambers; lopposed! impellers carried by and in driving relation with said shaft, one of said impellers being positioned in each chamber; and means providing leakage from said high pressure chamber to said low pressure chamber to at all times insure a predominant axialA thrust of the impellers towards the low pressure cham-- ber.

6. In a tion of: a housing forming a low pressure chamber and an adjacent high pressure chamber; a drive shaft 'extending through said chambers and provided with an abut ment; impellers slidable on said shaft and rotatable therewith, one of said impellers being positioned 1n each chamber; and

centrifugal pump, the combina-` means providing interchamber leakage insuring a predominant axial thrust ofthe impellers towards said abutment.

7. In a centrifugal pump, the combinai ment; and an impeller slidable on said shaft and rotatable therewith and positioned within said chamber, said impeller 4 being adapted to exert an axial thrust maintaining it in engagement with said abutment.

`8. ln a centrifugal pump, the combination of: a housing forminga low pressure chamber and an adjacent high pressure chamber; a drive shaft extending through said chambers; and opposed propellers carried by and in driving relation with said shaft, one of said impellers being ,positioned in each chamber and the housing being formed to provide leakage from` said high pressure chamber to said` low pressure chamber to at all times -insure a predominant axial thrust of the impellers vtowards the low pressure chamber. f i E 9. In a centrifugal pump, the combinau tion of: a housing forming a low pressure chamber and an adjacent high pressure chamber; a drive shaft extending through said chambers and provided with an abutment; and impellers slidable on said shaft.

and rotatable therewith, one of said impellers'being positioned in each chamber and the housing being formed to provide interchamber leakage insurin nant axial thrust of the impe ers towards said abutment. y

10. Ina multi-stage centrifugal pump of the opposed impeller type, the combination of: a housing forming a low pressure cham- MICHAEL E. wALTERs. ARTHUR R. wEis.

a predomi-

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