US2255545A - Submersible well pump lubricating system - Google Patents

Description

Sept. 9, 1941. J. M. HAIT SUBMERSIBLE WELL- PUMP LUBRICATING SYSTEM Filed April 18, 1958 2 Sheets-Sheet 2 no; fiil'llllll kouwkwkmv M w 5 W m 1 H M s 6 1 m r M tread Sept. 9, 1941 SUBMERSIBLE WELL m svs'mn nunarcarnvo James M. Halt, Les Angeles, Calif., assignor to Food Machinery Corporation, a corporation of Delaware Application April 18, 1938, Serial N0. 202,603

8Claims.

This invention relatesgenerally to submersible well turbine pumps such as are used in pumping water wells for domestic or industrial purposes. More particularly, this invention relates to methods of and apparatus for lubricating the motor of a submersible well pump and for returning lubricant to the surface without permitting its escape into the well liquid.

The invention as disclosed in this application is particularly designed for use in combination with or as a part of a submersible well pump wherein the motor is located below the impellers of the pump, however, the invention is also applicable to submersible pumps wherein the motor is above the impellers, such as disclosed in my 00-- pending application for patent on a submersible pump, filed of even date herewith.

' The difficulties with the present submersible an object to provide means in this chamber to prevent the .ubricant from reaching a point where it might escape into the well liquid.

It is a further object of this invention to entrap lubricant which escapes from the motor and to provide for the substantial separation of the lubricant from any well liquid with which it may have become associated after it has escaped from the motor. It is also an object of this invention to automatically return the separated lubricant to the surface of the ground.

These and other objects will be apparent from the-drawings and the following description thereof. Referring to the drawings, which are for the motor but do not make provision for preventing contamination of the well liquid by leakage of the lubricant from the motor. As far as I am aware, no positive means has been provided for repelling the entrance of the well liquid into the motor housing except such constructions as employ a mercury seal.

It is a primary object of this invention to provide a new and improved submersible well pump with'means associated therewith for supplying lubricant to the motor and for preventing escape of the lubricant into the well liquid. 7

It is also an object of this invention to provide a method of lubricating and positively repelling the entrance of well liquid into the motor housing by the use of lubricant. To accomplish this, lubricant is supplied to the motor housing at sufficient pressure to accomplish the purpose desired and to assure positive flow of lubricant from the motor housing outwardly. It is also an object to utilize pressure operable motor control means adapted to stop the motor when the pressure in the motor housing drops below a' safe amount relative to that pressure existent outside of the motor.

vIt is a further object of this invention to incorporate as part of the submersible well pump assembly a thrust bearing seal for controlling the escape of lubricant from the motorhousing.

It is a still further object of this invention to provide a chamber between the point at which lubricant may escape from the motor housing and the well liquidfor the entrapment of lubricant escaping from the motor housing. It is also illustrative purposes only,

Fig. 1 is a sectional elevation of a submersible well pump including the apparatus of this invention for lubricating the motor of the pump.

' Fig. 2 is an enlarged fragmentary sectional elevation of the thrust bearing seal located at the upper end of the motor housing and shown in Fig. 1.

Fig. 3 is a sectional elevation of the valve used in the accumulator and separator apparatus.

Fig. 4 is a sectional elevation of a form of lubricant deflector applicable for use in the entrapment chamber of Fig. 1.

Fig. 5 is a sectional elevation of another form of lubricant deflector applicable for use in the entrapment chamber of Fig. 1.

Fig. 6 is a diagrammatic view illustrating the lubrication system.

More particularly describing the invention, reference numeral ll indicates a delivery pipe which is supported at the surface of the ground and serves as a conduit for the pumped liquid. At the lower end of the delivery pipe is a pump bowl l2 which houses an impeller (not shown). Reference numeral l3 indicates a suction manifold, the lower end of which has attached thereto in any suitable manner a casing M. This casing has a partition wall l5 which divides it into an upper portion 16 having perforations it which form a strainer inlet for the well liquid. The lower portion I! of the casing, together with the partition member l5 and the upper portion of the motor housing, later to be described, form what will be termed an entrapment chamber I8.

Reference numeral l9 generally indicates an electric motor which is enclosed by a motor housing 20 comprising a lower section 2| and an upper section 22 which are secured together in any suitable manner so that the joint will be fluid tight. A motor shaft 23 is provided which is s mp rted by ball bearings generally indicated by reference numerals 24 and 25. The shaft carries a rotor-2i which rotates within the stator element. 21. The motor shaft 23 extends through the motor housing, a thrust bearing sealgenerallyindicatedbyreferencemnneral3tl,

and'whichwill subsequentlybedescribedin do tail, being provided in the region of the place where the shaft extends through the housing. Themotorshaftflisconnectedtoanimpeller shaft 32 through the medium of two universal joints, generally indicated by reference numerals 33 and 34 and a short coupling shaft 35 between the aforementioned joints. The impeller shaft 32 carries the impeller, not shown, but which is located the bowl II.

is provided a lubricant supply pipe 38 which leads from a suitable source of lubricant, preferablylocatedintheregionofthesurfaeeof the ground. The lubricant supply pipe is provided with a pressure regulating valve 39, shown diagrammatically. This valve is designed. to prevent excessive pressure of lubricant within the motor, and accordingly should be adjustable so that it may be set for different pressures, depending upon the particular installation. greaterthepresureofthewellliquidintheregion of the motor housing, the corresp greater lubricant pressure will be required in the motor housing.

It is an object of this invention to provide for the lubrication of the motor and also to provide for the positive prevention of entrance of well liquid into the motor housing by repelling entrance of such liquid by causing positive flow of lubricant from the motor housing outwardly thereof at the only point where the well liquid might enter the housing. To accomplish this itisnecessarytofeedthehibricanttothemotor atapressureinexcessofthepressureofthe wellliquidintheregionwherethewelllilmid might enter the motor housing. In most installationsthe colmnnoflubrlcantinthelubricant supply pipe 38, which would u lead from the lubricant supply at the surface of the ground, would provide suflicient head to provide the necessary pressure within the motor. It is contemplated, however, that m some installations itmaybe ntoinclude alubricant pump between the source of supply of lubricant and the motor for the of providing the necessary pressure and this pinup has been included in the of the lubricatingsystemshowninlilg.6,andlatertobe described.

Lubricant escapes from the motor through a thrust bearing seal, generally indicated by reference mnneral 30, into what will be termed an entrapment chamber ii. A sleeve bearingflmountedontheupperendofthe upper section 22 of the motor housing by means of suitable bolts 43 causes the escaping lubricant to follow the shaft 23 a considerable distance into entrapment chamber [8 before it can escape into the outer portions of the entrapment chamber. The details in the construction of thethrustbearingsealiill arebestillustratedin packing members 5!. The packing is compressed into sealing engagement with the shaft and the sleeve by means of a compression spring 52 located between a slidable collar 53 and a collar 54 which is g y mounted on the shaft by means of a set screw 55. Other means of sealing the shaft and sleeve may be used, however. Pressure of liquid in the chamber 58 serves to further compress the packing 5| and to increase the and thrust of the sealing sleeve 48 against the inner race 49 of the bearing 41.

The bearing sleeve 42 has a machined inner end face 42 so that a precision fit may be achieved between the stationary inner end face 42' of the sleeve 42 and the sealing end face 48' of the sleeve 48. A portion of the sealing end face 48' of the sleeve 48 bears upon and is supported by the inner race 49 of the hearing. The hearing is pre-loaded'so that precision fit is secured between the sealing faces 42'-48' which is virtually a metal to metal fit, the surfaces being separated only sufficiently to accommodate a very thin oil film. The fact that the ball bearing is pro-loaded to take care of the thrust load of the sealing sleeve 48 prevents wear of the sealing faces 42'48' inasmuch as, regardless of the in the chamber 58, the sealing faces can never be forced into engagement.

With the construction just outlined, the lubricant under pressure in the motor housing escapes from the chamber 58 gradually through the ball bearing 41, the lubricant passing between the inner and outer races, and over the top of the inner race and downwardly between the inner race and the bearing sleeve 42 to the region of the seal formed by the surfaces 42'--48' and then upwardly through the bearing sleeve 42 stated.

To prevent escape of the lubricant into the well liquid, the entrapment chamber [8, above referred to, is provided. The upper portion of this chamber, formed by the partition wall I5, is provided with 9. depending sleeve portion 60 which accommodats a. bearing 6!. Between the lower end of the bearing GI and the upper end of the sleeve 42 there is positioned suitable lubricant deflecting means; generally indicated by reference numeral 62. This oil deflecting means may take several'forms, and is provided for the purposeof preventing the escaping lubricant issuing from the upper end of bearing sleeve 42 from escaping outwardly through bearing GI and into the'well liquid.

In Fig. 1 one form of oil deflector has been shown'ss comprising a double-aproned member 63 which is secured to the shaft and rotates therewith. Such member is efiective to prevent lubricant gaining access to the lower end of bearing BI and is efiective to cause lubricant to accumulate in the upper portion of the entrapment chamber at a point above the lower end of the bearing 6|.

Adistinct advantage of the downwardly projecting skirt 53' lies in the fact that as 011 issues from the motor assembly it willrise through the, clearance inside of sleeve 42 and before escaping to the entrapment chamber it must pass downwardly out, around the upward projecting section of the sleeve 42', and in so doing creates an oil seal serving the purpose of preventing water from ingressing into the motor assembly when the pump is not in operation, or when, as might occur during non-operative periods, the pressure in the motor assembly may be below that which would exist during operation. For instance, if this downwardly projecting sleeve did not extend below the upward projecting sleeve 62, if the motor assembly should stand idle for a period of months, the pressure within could not be maintained in excess of that outside to cause leakage, and water might, by virtue of the difi'erence in specific gravity, seep in through the seal.

In Figures 4 and 5 there are illustrated two other forms of oil deflectors. A small impeller 85 may be located at the lower end of the bearing 8| mounted on the shaft. This impeller would serve to create a slight decrease in pressure in the region of the lower end of bearing BI and serve to slightly increase the pressure in the outer regions of the entrapment chamber. With this construction lubricant cannot enter the lower end of bearing 6| 5 illustrates the use of a disc 66 which might be mounted on the shaft at the lower end of the bearing Iii and which would be efiective to deflect lubricant flowing upwardly in the chamber around sleeve 69 so that the lubricant would accumulate in the upper portion of the entrapilient chamber above the lower end of bearc Leading from the upper end of the entrapment :hamber l8 there is provided a conduit 88 which extends upwardly into the lower portion of a .ubricant accumulator and separator apparatus, generally indicated by reference numeral 10. This apparatus is of the type disclosed and :laimed in my co-pendling application for patent in Automatic 011 return system for turbine pumps Serial No. 133,372.

Theaccumulator and separator apparatus generally comprises a casing II surrounding the lelivery pipe II and provided with a partition 12 vhereby a closed upper chamber 13 and a lower :hamber 14, which is open to the well liquid, are )IOVidEd. The upper chamber 13 is in communi- :ation with the interior of the delivery pipe hrough the medium of a port 15 which is located 55 n the lower portion of the upper chamber. Leadng from the upper portion of the upper chamber 5 a lubricant return conduit 18 for'returning luricant from the accumulator and separator apuaratus to the surface of the ground. Mounted n the partition 12 i a normally open valve ll vhicll is closable by pressure in the upper chamer In the operation of the accumulator and sepaator apparatus, lubricant enters the lower chamer [4 by means of conduit 68 and accumulates elow the partition l2 during the operation of the \ump. Inasmuch as the pressure in the chamer [3 exceeds that in chamber 14 by reason of he communicating port 15, the valve '17 remains losed. When the pump is stopped, the valve, 'hich is spring loaded, opens and permits escape f the lubricant into the upper chamber where accumulates in the upper portion thereof and 1 conduit 16. When the pump is again started, 75

' bearing seal 30 and into the the pressure in the upper chamber forces the lubricant to the surface of the ground.

One form of valve which has been found suitable for use in this apparatus is shown in Fig. 3

and comprises generally a valve centrally bored at 8|, the bore terminating in a valve seat 82. Above the valve seat the valve body 80 is hollow and provided with the openings 83. Mounted in the top of the valve body is a cap member 84 centrally apertured at 85 and having a depending sleeve portion 86 to accommodate a valve stem 81 which has a metallic conical head 88 adapted to fit valve seat 82. The valve is spring loaded and includes a compression spring 89 between cap member 84 and the washer 90 which is held in place by the nut 9|. Adjacent the head 88 is an oil resisting resilient sleeve 92 which swells into place when the valve is in contact with the seat. In the event abrasives or other material should prevent the metallic valve from fitting tightly, the pressure above the resilient ring will compress it into engagement with the inner surface of the valve body and seal any leakage which might take place past the metallic surface of the valve.

It is, of course, within the scope of the invention to eliminate the accumulator and separator apparatus and return the lubricant directly to the surface of the ground.

In the operation of the lubricating system, a

lubricant supply (see Fig. 6) is provided at the surface of the ground. This is connected to the pump by means of the lubricant supply pipe 38. Positioned between the two elements is the pres sure regulator valve 39 above referred to, designed to prevent excessive pressure in the motor housing in order to avoid excessive leakage. In some installations it may be necessary to provide a lubricant pump in order to secure the necessary pressure of lubricant in the pump housing, and this is shown in the diagram of Fig. 6. Suitable valves 95 and 96 are provided for controlling the flow of lubricant and for the optional use of the lubricant pump. It is to be understood that not all installations require the use of a lubricant pump and the lubricant pump has been included in Fig. 6 as an optional element.

Lubricant passing down the lubricant supply I pipe 38 enters the motor housing at the predetermined pressure, which is in excess of the pressure in the region of the strainer I 5. Lubricant flows outwardly through the thrust entrapment chamber l8 where it accumulates in the upper portion thereof and is prevented from escaping into the well liquid through bearing Bl by lubricant deflectors 82 which may take various forms as herein above described.

Some well liquid may enter the chamber I8 through bearing BI and consequently lubricant in chamber l8 will become mixed with water or well liquid to a certain extent. Positive flow of lubricant upwardly through bearing sleeve 42 prevents entrance of any well liquid into the motor housing, however. Since the lubricant in chamber l8 may become mixed with the well liquid, the liquid which flows upwardly in conduit 88 may be a mixture of lubricant and well liquid, especially after the pump has been in operation for some period of time.

Liquid flowing upwardly in conduit 68 is discharged into lower chamber 14 of the accumulator and separator apparatus I9. The lubricant tends to separate from the well liquid in this chamber and accumulate beneath partition submerged motor by use I2 during operation of the pump. When the pump is stopped the valve I'l opens and permits the lubricant to escape into the upper chamber 13 where it rises to the top. Upon restarting of the pump, the lubricant is forced to the surface through lubricant return pipe 16 which may lead to the lubricant supply.

ing said shaft, the upper portion of said casing means forming a depending sleeve extending a substantial distance into said entrapment chamher; a bearing interposed between said sleeve The accumulator and separator III, to function properly. must necessarily have its lower end substantially submerged in the well liquid during operation, and the upper portion thereof, 13, must be submerged during non-operating periods in order to float the oil from the lower portion of accumulator l4, and the lower end of the casing should at all times be below the surface of the well liquid.

Extending from a suitable source of electricity is an electric cable 98 which is supported on the conduit 38 by means of suitable clamps 99. This cable connects the motor to the source of electricity and to suitable control means and also connects in circuit with those elements a pressure operable electric control device Ilill.

' This device should preferably be of a type operable by the diflerential of pressure existent within and without the motor housing and for this purpose there is provided a port llll in the motor housing to establish communication between the interior of the device and the exterior of the motor housing. The control device is designed to stop the motor when the pressure in the motor housing drops below a safe minimum rela tive to the pressure existent externally of the motor housing.

Although this invention discloses means for feeding lubricant to a submersible motor and for returning that lubricant to the source of supply, it is within the scope of this invention to feed lubricant to the motor under pressure and to permit escape of that lubricant into the well liquid at a point above the suction intake of the pump. Thus, lubricant might be permitted to escape at the upper end of conduit 68 directly into the well liquid instead of into an accumulator and separator structure from whence means is provided for returning lubricant to the surface of the ground. In other words, the invention also contemplates the lubrication of a of a lubricant feed to the motor under pressure with means for bypassing such lubricant as it escapes from the motor past the point at which the well liquid enters the pump so that lubricant will not contaminate" the well liquid in the region where it enters the pump.

I claim as my invention:

1. In apparatus of the type described, the combination of: a submersible motor enclosed by a housing having a shaft extending through said housing: casing means forming an entrapment chamber adjacent said motor housing surroimding said shaft; means for delivering lubricant to said motor under pressure; a thrust bearing seal surrounding said shaft in the region where the shaft passes through the motor housing, said sealbeingadaptedtopermitalimitedflow of lubricant from the motor housing into said entrapment chamber; and means for conducting hibricant from said entrapment chamber to a desired point.

2. In apparatus of the type described, the combination of a submersible motorenclosed by a housing having a shaft extending through said housing; casing means forming an entrapment chamber adjacent said motor housing surroundand said shaft; a lubricant deflector mounted on said shaft below said sleeve for preventing lubricant from escaping through said bearing; means for delivering lubricant to said motor under pressure; meanssurrounding said shaft in the region where the shaft passes through the motor housing and into the entrapment chamber providing a restricted passage of predetermined dimensions; and means for conducting lubricant from said entrapment chamber to the surface of the ground.

3. In apparatus of the type described, the combination of: a submersible motor enclosed by a housing having a shaft extending through said housing; casing means forming an entrapment chamber adjacent said motor housing surrounding said shaft, the upper portion of said casing means forming a depending sleeve extending a substantial distance into said entrapment chamber; a bearing interposed between said sleeve and said shaft; means on said shaft for reducing the pressure at the lower end of said bearing and for causing flow of liquid outwardly from that region to the outer portions of the entrapment chamber; means for delivering lubricant to said motor under pressure; means surrounding said shaft in the region where the shaft passes through the motor housing and into the entrapment chamber for permitting a limited flow of lubricant from said motor housing into, said entrapment chamber; and means for conducting lubricant from said'entrapment chamber to the surface of the ground. a

4. In a submersible motor adapted for operation in a well, the combination of: housing means forming a motor chamber having an opening at its upper end; a motor in said chamher; said motor chamber being filled with, oil; a shaft extending from said chamber out through said opening; casing means forming an entrapment chamber surrounding said shaft immediately above said motor chamber, said casin means forming 9. depending sleeve extending a substantial distance into said entrapment chamber; a bearing in said sleeve journaling said shaft; means for supplying said motor chamber with oil at a pressure sufiicient to cause said oil to flow from said motor chamber into said entrapment chamber; and means for conductin liquid from the upper end of said entrapment chamber from a point above the lower end of said sleeve to a point out of the well.

5. In a submersible motor adapted for operation in, a well, the combination of: housing means for forming a motor chamber having an opening at its upper end; a motor in said chamber; said chamber being filled with oil; a shaft extending from said chamber out through said opening;

' casing means forming an entrapment chamber ower apron extending over said upwardly exending sleeve means-for supplying said motor hamber with oil at a pressure suiiicient to cause aid ofl to flow from said motor chamber into aid entrapment chamber; and means for coniucting liquid from the upper end of said entraplent chamber from a point above the lower end I lsaid depending sleeve to a point out of the re 6. Oil entrapment means for use in combinai011 with a chamber from which a shaft extends mi from which oil is extruded comprising: ousing means forming an entrapment chamber mrrounding said shaft immediately above said hamber, said housing means forming a dependig sleeve extending a substantial distance into dd entrapment chamber surrounding said shaft; leans forming an upwardly extending sleeve round said shaft; oil deflector means mounted a said shaft intermediate the two sleeves; and

leans for conducting entrapped oil from said itrapment chamber, the inlet of said conducting being located at a point above the lower id of the depending sleeve.

7. Oil entrapment means for use in'combinaon with a chamber from which a shaft extends [(1 from which oil is extruded comprising: hous g means forming an entrapment chamber surmmding said shaft immediately above said first mentioned chamber, said housing means having an opening in its upper end surrounded by a sleeve projecting downwardly from the upper vmentioned chamber, said housing means having an opening in its upper end surrounded by a sleeve projecting downwardly from the upper wall of said housing and through which said shaft extends, a portion of said entrapment chamber being located above the lower end of said sleeve; an oil deflector mounted on said shaft below said sleeve and having a portion surrounding said sleeve: and means for conducting entrapped oil from said entrapment chamber, the inlet of said conducting means being 7 located above the lower end of said sleeve.

JAMES M. HAIT.

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