US2161862A - Method and apparatus for protecting pump bearings - Google Patents

Description

June A J. M. HAIT A METHOD AND APPARATUS FOR PROT'CTING PUMP BEARINGS Filed March 2o, 193e 's sheets-sheet 1 1W- v @www l., l v cfa/m95 14. A70/'2L June 13, 1939. .l` M. HAIT 2,161,862

METHOD AND APPARATUS FOR PROTECTING PUMP BEARINGS Filed Maren 2o, 193e 3 sheets-sheet 2 June 13, 1,939. J. M. HAIT METHOD AND APPARATUS FOR PROTECTING PUMP BEARINGS .3 Sheets-Sheet -3 Filed March 20, 1936 66v j 15 zal c I d 40' i l y 95 eamef-M Hal/' Patented June 13, 1939 UNITED STATES METHOD AND APPARATUS FOB PROTECT- ING PUMP BEARINGS James M. Hait, Los'Angeles, Calif., assignor to Food Machinery Corporation, a corporation of Delaware Application March zo, 193s, serial No. 69,923

6 Claims.

This invention has to do in a general way with deep well turbine pumps and is more particularly related to the design and operation of the line shaft bearings which are located in the pump assembly or the pumping mechanism below the conventional b '-pass port which is generally located in the discharge fitting associated with and mounted on the uppermost bowl in the assembly.

l0 As is well known to those familiar with the art, considerable difficulty is experienced in turbine pumps of this character, especially when they are being operated in wells containing sandy water, due to the fact that a pressure differential exists between the ends of the variousbearings in the pump assembly and a certain amount of fluid iiow consequently takes place through the bearings due to this pressure differential, such fluid ow carrying with it sand particles which eventually cut out the bearings. Various attempts have been made to remove this condition. For example, seals of various kinds have been used with little or no success and under certain circumstances vit has been proposed to conduct a clarified high pressure fluid down into the Well through auxiliary lines and deliver this fluid into the space between the shaft and the bearing, the pressure of this fluid being maintained at a value sumcient to repel the normal tendency of seepage which arises from the differential pressure between the ends of the bear- 'I'his procedure is met ings referred to above. with diiliculty and expense of running a small auxiliary line or a plurality, of such lines into the well from the surface of the ground either inside or outside of the pumped fluid delivery tubing. In, an effort to overcome this difllculty it has also been proposed to deliver :duid directly from the delivery tubing in the region of the pump assembly into the bearing and to remove the sand and abrasive matter from the fluid delivered in this manner by means of a filter. The use of aillter in thisA connection, however, meets with two difficulties which render it impractical, if not absolutely inoperative. In the first place,

when the pressure fluid is taken from the region of the pump assembly itself and is supplied within the bearings in this same region, the maximum pressure dilerential which can be obtained under certain circumstances will be so small that the resistance oiered by a lter will counteract the differential, making it impossible to supply sufficient uid pressure within the bearing to repel the normal tendency of uid flow sa therethrough.. Furthermvre, the filter will be- (Cl. 10S-102) come clogged with sand and sediment after a very short period in operation which will completely obstruct the flow of fluid therethrough and consequently render the device inoperative.

It therefore becomes a primary object of this 5 invention to provide means for counteracting the normal tendency for fluid flow through the bearings of a deep well turbine pump by applying fluid pressure within the bearing and obtaining such pressure within the region of the pump 10 assembly.

It is a further object of this invention to provide a means of the class described in which the pump bearings are supplied `with clarified fluid obtained in the manner above referred to. i5

It is, as pointed out above, a primary feature of this invention that the fluid which is delivered into the space between the bearing -and the shaft is obtained from the pumped uid delivery tubing and my invention contemplates a 20 novel means and method of obtaining the fluid in this manner in an open conduit arranged and constructed so that the velocity of flow through the conduit is insulcient to support and carry the sand particles contained in the main stream 25 flowing through the delivery conduit.. In other words, my invention contemplates the use of a small pressure conduit which has a substantially vertical leg portion opening downwardly into the fluid stream in or immediately adjacent the de- 30 livery conduit at a predetermined pressure zone, such pressure conduit having an outlet or discharge opening adjacent the shaft in the region of the bearing. The position of theinlet opening for this pressure conduit is such i( that the 35 pressure at this point is greater than the pressure normally 'tending tocause flow through the bearing in ,question and the system is arranged either'through the use of a very small pressure differential -between the ends vof the bearing in 40 questionl orthrough the use of seals associated with thefbearing so that the velocity of flow in thel pressure conduit is below that which will support and carry sand particles ordinarily .suspended in the uid stream. 45

My vinvention therefore contemplates the use of an open ended stilling or settling chamber' positioned with its open bottom end opposed to the direction of flow in the pumped stream so that the sand particles settling from the fluid 50 in this stilling chamber are picked up and carried away by the fluid stream. By arranging the stilling chamber with-its opening opposed to the direction of flow, I always obtain the maximum pressure in the region of such opening since such 4o A"is in threaded engagement with the lower 'end pressure is a composite'of thea static and kinetic 'pressures at. that point.

Details in the construction and operation of for illustrative purposes only and in which Fig. 1 is an elevational view with parts broken away showing the pump assembly and intake manifold 'of a deep well turbine pump equipped with certain preferred embodiments of -my invention.

Fig. 2 is an enlarged sectional elevation taken in a plane represented by the line 2-2 o1' Fig. 1.

Fig. 3 is a plan section taken in a plane represented by the line 3-3\of Fig. 2.

Fig. 4 is an enlarged plan section taken in. a piane represented by the line 4;-4 of Fig. 1.

Fig. 5 is an offset sectional elevation taken along the line 5 5 of Fig. 4.

Fig. 6 is an enlarged sectional elevation taken along the line 6--6 of Fig. 1 and illustrating details in the construction of a preferred form of bottom line shaft bearing contemplated by this invention.

Fig. 'I is a fragmentary sectional elevation taken along the line I-'I of Flg..3.

Fig. 8 is an enlarged fragmentary sectional elevation taken along the'line 8-8 of Fig. 5, and

Fig. 9 isa fragmentary sectional elevation illustrating a modification ofthe top bearing construction shown inyFig. 5. f

Moretfparticularly describing the invention as herein illustrated, reference numeral II indicates a pumpassembly or pumping mechanism which 'embodies' a plurality of bowls indicated generally by refereirice'- numerals I Ia, IIb `and IIc. 'I'he uppermost ybowl Ila is shown'las being formed in' combination with a discharge manifold generally indicated by reference numeral I2 lwhich of apumped'fiuid deliverytubing I3. The botcom bowl ne" isshown as; being connected with an intake manifold Il which in turn is connected through'the medium of a pipe I5 with a strain- 'The' bowls I I a etc. are of any conventional construction ea'ch being 'equipped with an impeller I 8, such impellers being keyed to a line shaft I9 which extends up through/a line shaft enclosing tubing 20 to the surface of .the ground where it is supported and driven by any conventional Adriving means not shown.

`It 'will be understood by those familiar with the art that the number of bowls may be varied, de-

"pending upon the depth of thevwell and the cai pacity desired in the pumping unit. In the event also has a radial bearing in the discharge manifold I2 and the lower end of the shaft I9 extends downwardly from the lowermost impeller in the bottom bowl IIc into the intake manifold I4 Where it hasa radial bearing in the housing' generally indicated by reference numeral 25.

'I'he housing 25 is supported in the manifold I4l by means of webbing 26 so as to leave a subsuantially open passage through the periphery Lmouillees t of the housing which forms a part of the pumped fluid delivery conduit. l I

- The intermediate bearing housing 23 as shown in Figs. 2 and 3 is provided with a hub portion 33 supported by webbing members 3I and 32 so as to leave a passage 33 therethrough for the pumped fluid, such hub member containing bearing sleeves 35 which support the section of the line shaft I3 which extends therethrough;

Likewise the discharge member I2 constitutes an open housing which has a hub member 33 extending axially therethrough, such hub member being supported by webs 39 and 39' (see Figs. 4 and 5) and having a bearing sleeve 40 mounted therein in engagement with the shaft As has been previously pointed out, it is a primary object of this invention to provide in a pump assembly of ythe class described, means for protecting the various bearing members therein from the abrasive action which normally results from the flow of fluid carrying sand `particles through the bearings, such flow being set up by the pressure di'erential between the opposite ends of the bearing. This object is accomplished in a general way by repelling suchA flow with clear uid delivered into the region adjacent the shaft in a manner and at a pressure such that the pressure of the cleariluid will oppose the pressure normally tending to cause flow of the sand laden fluid. It was also pointed out that the chief object of this invention was to obtain the pressure fluid so used directly from thel pumped stream in a manner such that it was clarified before delivery to the space ube tween the shaft and the bearing.

In Figs. 2 and 3 I show one form of nstruction which may be employed to eect the foregoing objects in the region of thev intermediate bearing 35. intermediate fitting 23 may be considered as comprising a housing having anges 46 and 45' at its ends for attachment to the adjacent bowl members. This housing as pointed out above,

has an axial hub 30 supported by webbing mem-l bers 3i and 32 which contains the. shaft bearings. In this form of my invention it will be observed that the bearing 35 is formed in segments so as to leave a space I3 at an intermediate point therein, such space being situated opposite a passage 49 extending through the webbing member 32 (see Fig. 7). This passage .49 communicates with a chamber 50 formed on the periphery of the housing 45, such 'chamber being closed at its upper end and having an opening 5I at its lower end within which a stand pipe 52 is mounted. The lower end of the stand pipeA 52 is pressed or otherwise tightly tted in the opening 5i and is of a length such that its upper open end 53 terminates at or near the top. of the cham- 'ber 50. The bottom of the pipe 52 is open.

It will be observed that the upper end of the bearing 35 is situated just below the intakeor suction portionl of the impeiler I8 in the bowl assembly yabove and since the bottom of the hub 30 is situated on the pressure side of the next lower impeller it will be observed that there is a pressure differential between the two ends of the hub 3B which normally tends to cause kseepage and iiow of pumped sand laden fluid into the hub and through the space between the shaft andthe bearing therein. It will be understood of course that the pressure differential between the ends of the bearings at this particular point is comparatively small and it will also be seen In this form of construction. theI miv that the pressure at the inlet'or mouth of the pipe 52 is greater than the pressure which normally tends to cause flow through the bearing. With this arrangement shown in Figs. 2 and 3, therefore, pressure fluid is delivered into. the space between the shaft and the bearing through the port 49 at an intermediate point between the ends of the bearing, the pressure of the iluid so delivered being sumcient to repel the normal tendency to now. In this arrangement also since the pressure differential is relatively small be" tween the ends of the bearing the velocity at which fluid will be delivered into the space between the shaft and the bearing from) the port 49 will be relatively low.

In other words, in the operation of this form of my invention pressure fluid from the pumped stream in the delivery conduit rises through the vertical leg or stand pipe 52 and is delivered into.

the upper end of the chamber 50 to b e subsequently delivered from the port 49 through openings 48 into the space between the shaft and the bearing where it tends to squeeze or seep in both directions and repel any tendency to ow from the ends of the bearing. This fluid is clarified of sand particles since as pointed out above the` velocity of flow through the system comprising pipe 52 and the chamber 50 is very small and is consequently insumcient to support and carry sand particles throughout the height ofthe leg or stand pipe 52. In this way the fluid delivered to the shaft bearing is a clear fluid and since any flow which takes place through the bearing must be comprised of this clear fluid, the cutting action normally encountered is eliminated.

In the form of my invention shown in Figs. 4 and 5, I illustrate one manner in which the same general principles described above may be applied to the bearing in the discharge portion or discharge fitting of the pump assembly. 'I'he discharge fitting I2 may also be considered as comprising a substantially open body having a iluid passage 6I) extending therethrough between the outer wall of the body and the hub 38.

As is well known to those familiar with the art it is conventional practice to provide the discharge fittings of turbine pumps with by-pass ports which establish connection between the bottom of the shaft enclosing tubing 20 and the water in the Well in order to prevent pumped iluid which seeps through the bearings from rising in the enclosing tubing.f Such by-pass ports in this form of my invention are shown as being.

provided in the webbing members 39 and are indicated generally `by reference numeral 6| in Figs. 5 and 8. It will be observed that the bypass conduit 6I communicates with the upper end portion of the hub member 38 in the region at whichthe bearing member 49 terminates and with this arrangement it will be seen that the pressure differential between the bottom of the bearing 49 and the upper end of such `bearing would normally be the di'erence between the pump pressure at the top of the uppermost stage and the pressure in the well at the region of the outlet uid by-pass port 6I. This last mentioned pressure would either be atmospheric in the event the top bowl assembly was above the water level in the well or at most it would be the static head resulting from the level of water above the bypass outlet. It will be seen therefore that-the greatest tendency for uid flow and consequently the greatest cutting action resulting from such ow with a sand laden iuid takes place in this bearing.

For the purpose of delivering a clear fluid into the space between the shaft and the bearing at a pressure which will repel such normal tendency to flow, I employ what may be termed a pressure fluid delivery pipe generally indicated by reference numeral 65. 'I'his pipe is shown as hav--v ing a U bend 66 at its upper end so as to provide a substantially vertical leg portion 61A which opens downwardly into the pumped fluid stream so that the pressure applied in the mouth of this vertical leg portion is the composite static and kinetic pressure resulting from the working head of the pump and the velocity of fluid flow in the delivery tubing. The lower end of the pipe 65 is mounted in a chamber 69 formed in the hub 38, such chamber having a duct 10 ported as indicated at 1I so as to discharge through a sleeve member 12 into a space 13 between oppositely disposed seal rings 14 and 15 which engage the shaft and are shown as being positioned below the bearing 40.

'Ihe reason for providing the seal rings 14 and 15 is to restrict the passage between the shaft and the bearing so that the velocity of flow between the shaft and bearing and the velocity of ow up through the vertical leg portion 61 is maintained suiliciently low to prevent sand particles being carried upwardly through the `full length of this leg. In other words, the passage referred to is restricted and the length of the leg 61 is chosen so that all of the sand normally carriedY by the iiuid stream in the pumped ,delivery tubing will settle from the fluid in the leg 61 before passing over the U bend 66. The leg 61 like the vertical pipe or leg 52 in Fig. 2 may therefore be considered as a settling chamber, the intake or mouth of which is positioned at a pressure zone in the pumped iluid stream which is greater than the pressure normally tending to cause flow through the bearingI adjacent which the conduit system including the leg 61 has its outlet.

In Fig. 6 I show an arrangement operating upon the same general principle discussed above which lends itself particularly to use in connection -with the bottom shaft bearing housing 25.

The housing 25 is shown as being provided with A a seal member at its upper end to restrict the flow of fluid for the same purpose discussed above, the bottom of such housing beingprovided with a cover cap 8| within which a downwardly extending open ended pipe or leg,4 82 is secured. 'Ihis leg 82 has its inlet end positioned in opposed relation to the direction of fiow as it enters the intake'manifold I4 so that the pressure applied in the mouth of such legis also a composite static and kinetic pressure which is greater than the pressure at the upper end of the housing which, as will be seen from Fig. 6, is immediately below the intakeor suction portion of the impeller I8. The seal 80 retards the ilow of uid between the lower end of the shaft and the bearing 25' and the length of the leg 82 is chosen so that at the velocity encountered' the sand particles will not be enabled to rise through this pipelinto the space between the shaft and the bearing. It will thus Ibe seen that this arrangement also is eifective to deliver a clear pressure fluid into the space between the shaft and the bearing through the medium of a vertical settling tube positioned with its mouth or inlet in the pumped uid stream.

In theform of my invention shown in Fig. 9 which is Va modification of the form shown in Fig. 5, I show the bearing 40' as being cut away in its outer portion to provide a space 90 extending above and below the discharge `9i from the pressure conduit system which includes a U bent delivery and settling pipe 66. In this formof my invention I employ sealing members 92 and 92' positioned above and belowthe ends of the bearing members 40' such bearing having a port 93 situated intermediate its ends, through which the clear pressure nuid' is delivered into the space between the bearing and the shaft.

It will be understood that while I have herein described and illustrated certain embodiments of my invention, that the invention is not limited to any of the precise structural details shown and described above, but includes within its vscope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. In combination with the pumping mechanism of a well turbine pump having a line shaft, a line shaft bearing and a pumped fluid delivery conduit: pressure conduit Ameans for delivering uid from a high pressure region in said delivery conduit into the space between said shaft and said bearing, said last mentioned means including a substantially vertical oiset pipe section opening downwardly toward the fluid stream in said delivery conduit and sealing means surrounding said shaft and associated with said pressure conduit whereby the ow of iiuid through said bearing is restricted and the flow in said vertical pipe section is thereby maintained of insuilicient velocity and turbulence to support sand particles therein.

2. In combination with a turbine well pump of the class described; a housing forming part of the pump assembly and having a passage therethrough forming part of the pumped liquid delivery conduit; a radial bearing in said housing; a line shaft extending through `said bearing in engagement therewith; a by-pass conduit formed in said housing with its inner vend communicating with the upper end portion of said bearing and its outer end opening `into said well; and conduit means for delivering clear high pressure liquid from said pumped liquid delivery conduit into the space between said shaft and said bearing at a point below said by-pass conduit said last mentioned pressure liquid conduit including a substantially vertical oset sand settling tube opening downwardly into the liquid stream. in said delivery conduit.

3. In combination with a turbine well pump of the class described: a housing forming part of the. pump assembly and having a passage therethrough forming part of the pumped liquid delivery conduit; a radial bearing in said' housing; a line shaft extending through said bearing in A engagementl therewith; a by-pass conduit formed in said housing with its inner end communicating with the upper end portion of said bearing and its outer end opening into said well;

conduit means for delivering clear high pressure liquid from said pumped liquid delivery conduit into the space between said shaft and said bearing at a point below said by-pass conduit, said conduit means including a pipe having a substantially vertical inlet portion with an inlet duit in said housing communicating with thel passage through said hub abovesaid bearing and having an outlet opening inV said well; conduit means for delivering clear high pressure liquid from said pumped liquid delivery conduit into the space between said shaft and said bearing.

at an intermediate point on said bearing, said conduit means Yincluding a pipe having a substantially vertical inlet portionl with an inlet opening at its lower end opposite the general` direction of liquid flow in said delivery conduit; and shaft sealing means insaid hub between the upper end of said bearing and said by-pass conduit.

5. In combination with a turbine well pump of the class described: a housing forming part of the pump assembly and having a passage therethrough forming part of the pumped liquid delivery conduit; a radial bearing in said housing; ai line shaft extending through said'bearing in engagement therewith; a by-pass conduit formed in said housing with its inner end communicating with the upper end portion of said bearing and its outer end opening into said well; and conduit means for delivering clear high pressure liquid from said pumped liquid delivery conduit into .the space between said' shaft and said bearing at a `point below said by.pass conduit, said last mentioned pressure liquid conduit including a'substantially vertical pipe having a U`bend at its upper end thereby providing a substantially vertical leg having an inlet opening at its lower end oppositelthe general direction mechanism, a rotary drive shaft, a bearing associated with said pumping mechanism and engaging said shaft, and housing means forming a liquid deliveryA conduit, means for delivering liquid free of solid particles to said bearing under a pressure greater than the pressure normally causing liquid flow through the bearing, comprising: conduit means connecting the interior of said bearing and said liquid delivery conduit, said conduit means having a'substantially vertical inlet tube offset from said bearing with the inlet opening opposed to the flow of the pumped liquid in said liquid delivering conduit, and means for restricting the flow of liquid through said conduit meanswhereby any solid particles held in suspension in the pumped liquid are allowed to settle from the uid entering said tube before the liquid reaches said bearing.

JAIMES M. HAIT.

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