US2166404A - Electrical impeller positioning device for turbine pumps - Google Patents

Description

J. M. HAI-r' 2,166,404

ELECTRICAL IMPELLERPOSITIONING DEVICE FOR TURBINE PUIPS July 18, 1939.

Filed May' 29, A195e;

Patented July 18, 1939 ELECTRICAL IMPELLER POSITIONIN G DE- VICE FOR TURBINE PUMPS James M. Hait, Los Angeles, Calif., assignor to Food Machinery Corporation, a. corporation of Delaware Application May 29, 1936, Serial No. 82,512

4 Claims.

'Ihis invention has to doin a general way with deep well turbine pumps and is more particularly related to improved means for positioning the impellers within the bowls of such pumps after 5 they have been installed in the well.

As is well known to those familiar with the art, the usual construction of the so-called deep well turbine pump embodies a suspended shaft known as the line shaft which carries at' or near its lower end an impeller or a plurality of such impellers which are enclosed'within corresponding bowl members that communicate with a discharge or conductor pipe leading to the surface of the ground. The usual shop practice in building and ll assembling the impellers within the bowls is to fit each impeller within the bowl with a certain amount of vertical clearance generally termed lateral. In deep wells, however, Where a considerable length of line shaft is used, the thrust load caused by the lifted weight of fluid being delivered by the pump causes the line shaft to stretch, thereby permitting the impellers to lower to some indetermined position which may not only lower the efliciency of the pump but fre- .l quently introduces friction caused by the impellers riding upon the bowls.

The factors last mentioned above have brought about the development' of various means for give ing an indication at the surface of the ground N after the pump has been started in the event the stretch of the line shaft'has caused the bowls to lower to or beyond a predetermined point. In my prior Patent No. 1,909,533, of which the present4 invention is an improvement, I have shown electrical means for accomplishing this purpose and it is a primary object of this invention to provide improved means of the general character disclosed in the prior patent just referred to in which the necessity of using an independent con- 4o ductor or independent conductors which extend from the surface of the ground to the region of the contact points in the pump unit, is eliminated. l

'I'his invention, therefore, contemplates electrcal signal or indicating means having vertically spaced contacts at or near the lower end of the pump line shaft in which the circuit leading to such contacts is comprised of the shaft itself and its associated encasement means. It should be 5o pointed out at this time that the term encasement or encasement means as it is to be used in the present application refers to the shaft enclosing tubi/ng or the delivery tubing which surrounds the shaft and the bowls which surround the im- 55 pellets, such encasement means being electrically (cl. 11i- 311) g insulated from the line shaft-impeller unit which, as the term implies, incorporates the line shaft and the impellers carried thereby.

It is a further object of this invention to provide in a device of the class described a novel Il form of contact unit which is especially adapted for use in connection with pump assemblies incorporating lateral seal rings for the bowl and impeller members that; are subject to wear. In devices of this character it is the practice to lower l0 the line shaft from time to time in order to accommodate or adjust for the wear which takes place in the lateral seal rings and the contact means contemplated by this modification of my invention incorporates a fixed member which 15 will be depressed by the line shaft when it is lowered to bring the impellers to rest on their respective seal rings and which will remain in this depressed position when the line shaft is adjusted vertically so that contact will be established and an indication obtained in the event the load causes the line shaft to stretch to a point at which the impellers reach a predetermined position relative to their respective lateral seal rings.

The details in the construction'of certain pre- 25 ferred forms of my invention together with other objects attending its production will be best understood from the following description of the accompanying drawing which is chosen for illustrative purposes only and in which:

Fig. 1 is an elevational view with parts in section illustrating a turbine pump assembly equipped with one embodiment of my invention;

Fig. 2 is an enlarged fragmentary sectional elevation illustrating details in the construction of one form of line shaft suspending unit and illustrating one manner in which the line shaft may be insulated from its associated easement means at this point;

Fig.4 3 is an enlarged fragmentary sectional 40 elevation taken along lth line'3L-3 of Fig. l, illustrating one form of insulated packing gland which may be utilized at the point where the line shaft extends through the discharge fitting;

Fig. 4 is an enlarged fragmentary sectional 45 elevation illustrating one form of insulated line shaft bearing which mny be used in conjunction with the 1device contemplated by this invention;

Fig., 5 is an enlarged fragmentary sectional elevation illustrating details in the construction of an impeller unit, such unit being shown with a lateral seal ring; and

Fig. 6 is `an enlarged fragmentary sectional elevation illustrating details in the construction of a base fitting contemplated by this invention,

such fitting being shown with a vertically adjustable bottom contact pin which is especially adapted for use in connection with the lateral seal ring shown in Fig. 5.

More particularly describing the invention as herein illustrated, reference numeral I I indicates what I have termed a line shaft-impeller u nit which consists of a line shaft I2 having impellers I3 rigidly mounted thereon. I'he line shaft-impeller unit is surrounded by what I have termed encasement means generally indicated by reference numeral I4, such encasement means comprising a discharge pipe I6 and bowls I6 and I6' which may be of any conventional construction and which are associated with impellers. The encasement means also incorporates an intake manifold II which carries a base fitting I9 into which the lower end of the line shaft I2 extends. In some types of construction the encasement means may also incorporate a shaft enclosing tubing but in the form of my invention shown herein, the shaft runs exposed within the discharge pipe and is supported at vertically spaced points by means of line shaft bearings generally indicated by reference numeral 20.

Since, as pointed out hereinabove, this invention contemplates the utilization of the line shaft and the encasement means as two separate conductors for connecting spaced contact points at the lower end portion of the line shaft with a source of potential at the surface of the ground for obtaining the electrical signal contemplated herein, it is important that the line shaft and the encasement means be electrically insulated from each other throughout their respective lengths. My invention therefore contemplates the utilization of line shaft bearings composed of electrical insulating material and while various types of insulated bearings may be employed to accomplish the object sought by this invention, I have illustrated in Fig. 4 the details in the construction of one preferred form of such bearing.

This bearing is shown as comprising a sleeve 26 supported by spider ribs 26 formed in a collar 21 which is also used to join adjacent sections of the conductor pipe. The bottom portion of this sleeve is formed with an annular shelf or shoulder 28 upon which a bearing sleeve composed of rubber or other suitable insulating material and indicated by reference numeral 29, is supported. The insulating bearing sleeve 29 is held in place against the shoulder 26 by means of a bushing member 30, the internal diameter of which is greater than the external diameter of the shaft so as to leave a substantial clearance between the shaft and this metal bushing.

In the form of my invention herein illustrated,

the top bowl member I6 is also shown as incorporating a discharge manifold 33 which has a hub section 34, such hub section having its inner surface spaced away from the shaft as indicated at I6 and being provided with a non-conducting or insulating bearing 36 which is held in place by a bushing member I6' similar to the bushing member Il in Fig. 4.

'Ihe impeller member Il shown in Fig. 1 is shown as being of the double shrouded type, but it will be understood by those familiar with the art that an open or single shrouded impeller may be employed. 'Ihe impeller Il is shown as being arranged with a bottom shroud III in vertically spaced relation with a top face 4I on the bowl I6', the shroud I0 having a downwardly 'projecting skirt I2 the lower edge of which is also in vertically spaced relation with a shoulder 43 in the top of the bowl I6. 'I'hese vertically spaced surfaces may, as will be pointed out hereinafter, be utilized as the contact surfaces for vcompleting an electric circuit through the shaftimpeller unit and the encasement means for energizing the signal to be hereinafter described.

The base fitting I9 is also shown as carrying a line shaft bearing I6 which is composed of insulating or non-conducting material and is shown as resting on a shoulder 41 and is held therein by means of a bushing member 46.

As another means of obtaining contact surfaces within the pump assembly for the purposes pointed out above, I show the bottom of the base fitting I9 as being provided with a threaded passage 6II which is in axial alignment with the line shaft, such passage containing a screw member 5I adapted for vertical adjustment therethrough. The screw member 5I is associated with lock nuts 52 for the purpose of holding the same in various positions of vertical adjustment.

In the form of my invention chosen for purposes of illustration herein, the top of the conductor tubing or delivery pipe I5 is shown as being secured in electrically conductive relation to a discharge fitting generally indicated by reference numeral 55. This discharge fitting is equipped with a box 56 through which the line shaft extends, the passage through such box being spaced radially away from the line shaft and being further provided with non-conductive packing indicated at 5l, such packing being held in place by a bushing member 56 which is also spaced away from the line shaft.

The upper end of the line shaft I2 is supported by a power head or driving unit 6I! which may be of any conventional construction incorporating either an electric motor or driving pulley. In the form shown herein the driving head 6l is shown as being in the nature of an electric motor, the upper end of the line shaft being provided with a driving collar 6I which is keyed to the line shaft as indicated at 62 and through which the line shaft is adapted to-be adjustably suspended by means of an adjustment nut 63. In this type of construction lthe collar 6I is supported by a hub member 64 which forms part of a rotor 65 in the electric motor. The hub 64 is carried by a hollow shaft generally indicated by reference numeral 66 which may be constructed and supported in any suitable manner well known to those familiar with the art.

In this type of construction in which the delivery pipe I5 'is directly connected to the discharge fitting and the discharge fitting is directly connected to the power head, such connections establishing electrical conductive relation between these parts, it is important that the drive shaft be insulated from the power head. In this form of my invention such insulated relation is obtained by interposing a non-conductive washer I0 composed of rubber or other suitable material between the collar member 6I and the hub member 64 and by enclosing the drive pin or drive pins II through which power is transmitted from the hub to the 'collar 6I, with an insulating sleeve 12. It will be understood of course that the hollow shaft 66 and all of the other elements through which the line shaft extends have their internal passages formed so that there is a substantial clearanceA between the line shaft and these other parts. f

'For the purpose of establishing an open electric circuit between the line shaft and the eneasement means in the device just described, I u

employ a source of potential indicated at S which is connected through a conductor Ci to any suitable point on the discharge fitting 55' or any other part electrically connected with the encasement means as indicated at 14. This source of potential is also connected to any suitable contact member which engages or may be pressed into engagement with the line shaft. In the form illustrated herein, I show a second conductor C2 which is connected with a plunger pin 15 carried in a non-conducting bushing 16 which in turn is supported by a bracket member 11. The pin 15 is held in its extended relation by means of a compression spring 18 and is adapted to be manually pressed into engagement with the line shaft I2 for the purpose of connecting the source of` potential S across the line shaft and the encasement means. The circuit thus formed is provided at any suitable point with asignal member19 in the nature of an electric light or a bell or buzzer which will give a sensible indication to the operator when contact is established between the line shaft and the encasement means at either of the points described hereinabove.

i In the device as illustrated above, which constitutes the simplest form of my invention, the pump unit is installed in the Well with Vthe parts arranged substantially as shown in Fig. 1, the screw 5I having been adjusted so as to leave the minimum clearance between the impellers'and the corresponding bottom surfaces` in the bowl members when it is engaged in the event such screw is to be utilized as the contact member for closing the circuit described above. The pump is then started in operation and the operator closes the circuit switch and if a signal is obtained in the indicator 19 he knows that the load and line shaft has stretched beyond the desired point of adjustment. rIhe pump is then stopped and the line shaft is raised a predetermined amount through the medium of the adjustment nut 63 after which it is started again, such procedure being repeated until no indication is obtained. As has been pointed out above, an indication may also be obtained without the use of the pin 5| in which event contact between the impellers and their corresponding bottom bowl surfaces is effective to give the indication above referred to.

In the impeller units shown in Fig. 5 in which the bowls are indicated by reference numerals |611. and I6b, it will be observed that the skirt 42a on the bottom shroud of the impeller I3a is formed so that it is positioned inwardly from the vertical edge 8l which surrounds the skirt. Positioned below the lower edge of the skirt 42a I provide what has been termed a lateral sealing ring 82 such ring being composed of a yieldable material such as rubber and constituting a seal between the successive bowls in the regions surrounding the impellers. It is necessary, however, in a construction of this character in order to prevent undue friction and wear on the rings, to maintain a slight clearance between the bottom of the skirt and the upper surface of the ring 82. Within very small limits and since the ring 82 is subject to some wear by the abrasive action ofv the fluid, it is necessary to adjust the impellers from time to time in order to compensate for this wear and maintain the small clearance neces- Sary l 'I'he procedure ordinarily followed in adjusting for this wear is to shut the pump down when the capacity drops off to a point which indicates that This clearance must be maintainedv the rings have become unduly Worn.` The position of the upper end of the shaft with respect to the adjustment nut B3 is then measured or a suitable reference mark is placed on the shaft after which the nut is loosened so as to drop the impellersdown on to the rings 82 in the bowls, thereby obtaining an indication as to the distance existing between the bottom of the impeller shroud and the lateral seal ring. The adjustment nut is then tightened to raise the shaft an estimated amount. Without the provision of an indicator, the amount that the adjustment nut was tightened to raise the shaft, might `not be sufficient to accommodate for the stretch inthe shaft when it is operating under loaded conditions and there being no way of indicating this the seal ring would be wor'n away to an excessive amount, decreasing its life in the well and in addition to that introducing an excessive frictional element. i

` The indicator contemplated by this invention,

therefore, is particularly useful in a combination of this character, but since the adjustment of the impellers with respect to the seal ring may be effected several times between periods of shutdown and withdrawal of the pump from the well, it will be seen that a rigid contact below the line shaft cannot be satisfactorily used where a number of such adjustments must be made. This invention, therefore, contemplates a contact member which may be depressed by the weight of the line shaft and which will remain in its depressed position so as to provide an indication of stretch in the line shaft aftera plurality of successive adjustments of the character just described above. In Fig. 6 I show one preferred form of such contact member in which it will be observed that` the base fitting lSa has a plug member 85 ythreaded into its lower end. This plug member carries a sleeve 86 which fits through a passage 81 in the bottom of the plug and is heldv in there in any suitable manner such as by means of set screws 88. Reference l numeral 90- indicates a contact pin which slidably extends through the sleeve member, such pin being frictionally held therein by means of packing 9| and a packing nut 92. In this form of my invention the packing is of a metallic or other electrically conductive material and the sleeve member 86 is also formed of a suitable conductive material so that conductive relation is established between the pin 90' and the encasement means of which the base fitting I 9a forms a part. With this arrangement, it will be seen that when the shaft is lowered for the purpose of adjusting or compensating for wear in thelateral seal rings 82 the lower end of the shaft or other contact means generally indicated by reference numeral 94 on the lower end of the shaft, will depress the pin 90 to a predetermined point when the impellers rest on the seal rings and that the pin will remain in this point after the shaft has been raised again a predetermined amount to compensate for the wear. In the event the load on the shaftcauses it to stretch to a point at which the seal rings are engaged, it will be seen that such stretching movement will bring the lower end of the shaft into engagement with the upper end of the pin y90 thereby closing the circuit to energize the signal or indicating member 19, and the operator then knows that the adjustment nut must be adjusted to raise the shaft an additional amount..

In the event the lower end of the shaft is depended upon to effect the adjustment of the pin 88 or in the event a rigid member in the lower end of the shaftis used for such movement, it will be seen that the signal will not be obtained until the impellers have actually been lowered into engagement with the seal rings and since it is important that a slight clearance be maintained between the impellers and these seal rings, I have shown in Fig. 6 a yieldable contact member for the lower end of the shaft which will raise relative to the shaft a predetermined distance corresponding to the clearance mentioned above before it is effective. to depress the pin. This contact member is shown as comprising a bushing I5 which is threaded into a pocket 96 in the bottom of the shaft, such bushing being provided with a bolt 91 loosely mounted therein and adjusted so as to leave a slight clearance A corresponding to the minimum desired clearance between the bottom of the impellers and the top of the seal rings, between the head of the bolt and the bottom of the bushing. The bolt is yieldably maintained in its depressed position by means of a compression spring 98.

When the shaft in this construction is lowered, the first action as pointed out above when the head of the bolt engages the pin 90 is to compress the spring n bringing the head of the bolt into engagement with the bushing. The continued downward movement of the shaft lowers the pin to a position at which it remains when the shaft is again raised. With this arrangement it will be seen that when the first contact is later established between the head of the bolt and the pin II with the shaft running under loaded conditions.' the impellers are positioned above the seal ring a distance corresponding to the clearance A between the head of the bolt and the bushing 95. The signal under` these circumstances is therefore obtained whenever the shaft is running with the minimum desired clearance or with less than minimum desired clearance and does not necessarily require that the impellers be drawn clear down into engagement with the seal ring before the circuit is closed.

It should be pointed out that under some well conditions the water may contain sufficient electrolyte to give it limited conductivity so that the signal may receive some current when the contact members are not engaged. 'Ihe resistance in such a circuit, however, is much greater than through the circuit completed by metallic contact so that the intensity of the signal will under these circumstances constitute a sensible indication of engagement between the contacts.

It is to be understood that while I have herein described and illustrated certain preferred forms of my invention, that the invention is not limited to the precise construction described above, but includes within its scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

l. In a deep well turbine pump, the combination of: a vertical shaft; encasement means surring; a contact pin slidably mounted in the bo*- tomof said encasement means below said contact member and frictionally held therein and adapted for engagement by said contact member upon downward movement of said shaft to complete an electric circuit through said source of potential; said shaft 'being adapted to reposition said contact pin downwardly when the bottom of the shaft lowers a distance in excess of the permissible movement of the contact member; and signal means in said circuit for giving a sensible indication when said circuit is closed.

2. For use in combination with a well turbine pump having a line shaft-impeller unit electricaliy insulated from its encasement means and having a source of electric potential connected across said line shaft-impeller unit and said encasement means, electric contact means comprising: a contact member resiliently supported in said line shaft-impeller unit for limited upward movement; and a contact pin frictionally slidably mounted in the bottom of said encasement means below said contact member and adapted for engagement by said contact member upon downward movement of said line shaftimpeller unit to complete an electric circuit through said source of potential, said pin being adapted to be depressed when said line shaftimpeller unit moves downwardly a greater distance than is necessary to cause said contact member to move upwardly relative to said line shaft-impeller the extent of its limited permissible movement.

3. In an apparatus for determining clearance between impeller and bowl in a deep weil turbine pump, the combination of a suspended impeller unit including a vertically adjustable line shaft. a casing surrounding said unit including a bowl normally spaced from said impeller unit during operation of the pump, means for vertically adjusting said line shaft relative to said casing to vary the clearance between said impeller unit and its associated bowl, means for electrically insulating said impeller unit from said casing and bowl, a source of electrical energy, means for connecting said source to said line shaft and said casing respectively to constitute said shaft and casing a part of a normally open electrical circuit, said impeller unit andsaid casing having vertically spaced electrical contact means adapted to be engaged upon predetermined vertical movement of said line shaft relative to said casing and bowl to close said electrical circuit through the line shaft unit and said casing from said source, and signal means included in said circuit adapted to be energized upon closing of said contact means.

4. In an apparatus for determining clearance between impeller and bowl in a deep well turbine pump, the combination of a suspended impeller unit including a vertically adjustable line shaft, a casing surrounding said unit including a bowl disposed adjacent said impeller unit and normally spaced therefrom during operation of the pump, means for vertically adjusting said line shaft relative to said casing to vary the clearance space between said impeller unit vand said bowl, driving means for rotating said impeller unit relative to said casing, means for electrically in' sulating said impeller unit from said casing and bowl including vertically spaced bearings of insulating material surrounding said line shaft and means associated with said casing for supporting said bearings, a source ofelectrical energy, means for connecting said source-to said line shaft and casing respectively to constitute said shaft and casing a part of a normally open electrical circuit, said impeller unit and said casing having vertically vspaced electrical contact means adapted to be engaged upon predetermined vertical movement of said line .shaft relative to said cas.

Ying and bowl to close said electrical circuit through the line shaft and said casing from said source, and signal means included in said circuit adapted to be energized upon closing of said contact means to sensibly indicate the engagement of and absence of clearance between said impeiler unit and said bowl. whereby the desirability for vertical adjustment of said line shaft land its impeller unit relative. to the casing and associated bowl to prevent undue wear thereon,

may be determined.

JAMES M. HAIT.

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