US 2293616 A
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Description (OCR text may contain errors)
Aug. 18, 1942. T. G. MYERS 2,293,615
' SUBMERSIBLE STRUCTURE Filed Feb. 28, 1938 4 Sheets-Sheet 1 lMVENTOR Thomas Myers I B 5 Jim/m;
1942- T. G. MYERS 2,293,616
SUBMERSIBLE STRUCTURE Filed Feb. 28, 1938 4 Sheets-Sheet 2 Source Compressed LNVENTOR SUBMERSI'BLE STRUCTURE Filed Feb. 28, 1958 4 Sheets-Sheet 3 INVENTOR Thomas 6;. M eras Wj/z/t ATTORNEY Aug. 18, 1942. T. G. MYERS 2,293,616
SUBMERSIBLE STRUCTURE Filed Feb 28, 1938 4 Sheets-Sheet 4 ATTO R N EY uNlTao STATE.
Patented Aug. 18, 1942 I SUBMEBISIBLE STRUCTURE Thomas G. Myers, Los Angeles, Calm, assignor to U. S. Electrical Motors, Inc., Los Angeles, Calif., a corporation California Application February 28, 1938, Serial No. 193,121
This invention relates to submersible structures; for example, to submersible electric motors adapted to be directly connected to pumps low ered into a well liquid. Installations of this general character have been proposed and used. They involve the problem of excluding theharmiul well liquid from the windings, as well as from the bearing structures. v
Various sealing devices for accomplishing these functions have been heretofore devised. In some of these, the motor casing is intended to be at least partially filled with an inert, neutral liquid that may also serve as a lubricant. In many instances, oil is a suitable liquid for this purpose. Problems however, arise in connection with such fillings and seals, which it is the aim of this invention to solve. These problems may now be discussed.
Whenever two unlike liquids are in contact, such as mercury and water, and when there is some agitation, an emulsion of the two liquids results. Where mercury is used as a sealing medium and in contact with the neutral liquid and the well liquid, this emulsification harms the seal. In cases where the neutral filling liquid, such as oil, is in contact with well liquid, such emulsification or mixture would in time seriously reduce the insulation quality or" the liquid in the casing, with-resultant serious effects upon the motor.
It is one of the objects of this invention to prevent harmful emulsiflcation or mixing of the liquids that are involved in systems of this character;
The manner in which this result is obtained may take several forms. Mechanical separation of the liquids in a novel way, forms another object of the invention.
It is still another object of the invention to make it possible to reduce the relative motion of liquids in contact, thereby retarding or preventing harmful emulsiiication.
This invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of several embodiments of the invention. For this purpose there are shown a few forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.
Referring to the drawings:
Figure 1 is a view, mainly in longitudinal section, illustrating a form of the invention in use in a well;
Figs. 2 and 3 are fragmentary views, mainly in section and on an enlarged scale, of modified forms of the invention;
Fig. 4 is a view similar to Fig. l of a further modified form of the invention;
Fig. 4a is an enlarged detail fragmentary sectional view of a part of the apparatus illustrated in Fig. 4;
Fig. 5 is an elevation of part of the mechanism illustrated in Fig. 4a;
Fig. 5c is a section as seen on plane 5a5a of Fig. in;
Fig. 6 is a view similar to Fig. l of a further modification; and
Figs. '7 and 8 are fragmentary views, mainly in section, of further modified forms of the invention.
' In Fig. I the well is shown as defined by a well casing l in which there is the well liquid 2. This well liquid may be water or the like which it is desired to pump out of the well.
For this purpose, use is made of a submersible electric motor, having the motor elements socommodated in a space 3 formed within a submersible casing 4. Within this space 3 there are accommodated the primary or stator windings 5; and the rotor 6 mounted on a rotary shaft 1.. The motor, comprising the parts and E, may be of the conventional induction motor squirrel cage type, appropriately connected through waterproof cables toasource of electrical energy at the top of the well.
The shaft 1, shown in this instance as extending upwardly out of the casing, is intended to be directly connected to a pump (not shown). Frovisions are made for insuring against the entry of well liquid within at least that part of the casing 3 in which the motor windings and the shaft are located. The manner in which this is done will now be described.
The rotary shaft 1 is shown in this instance as being supported for rotation by a lower ball bearing structure 8, the outer race of which is supported on a transverse perforated wall 9 extending across the bottom of casing 4. Adjacent its upper end the shaft 1 is similarly rotatably supported by the ball bearing structure it. The outer race of this ball bearing structure is shown in this instance as supported on a spider I I, having the flange 12 secured to an integrally formed flange 13 extending inwardly from the wall of casing 4. In the present instance, the casing 4 I may be filled with a neutral liquid or gas, such as oil, carbon tetrachloride, or air. When the casing is filled with gas or air, it is desirable to have a layer of oil on top of the water to prevent absorption of the gas in the water.
The top 'or cover I5 of casing 4 is a flexible, corrugated diaphragm securely fastened in fluid tight manner to the casing, and has an aperture I6 through which the shaft 1 extends. In order to provide a fluid tight seal around the shaft I,
I the area of the top surface of the liquid I8 is divided so that a part of it is in contact with the filling in the casing 4. The inner annular part would normally be exposed to well liquid 2. In
order for well liquid to pass into the casing it would have to pass through the inner annular portion of the liquid I8, around the lower edge of the non-rotary sleeve I9, and again upwardly through the outer annular portion of liquid I8. There is thus a liquid sealing efieot provided by the elements just described.
In order to prevent any whip or vibration of the shaft 1 due to wear of the supporting bearings or other causes, from being imparted to the liquid filling in cup I I, along with the rotary movement of the shaft, means are provided to prevent relative lateral motion between cup I! and the sleeve I9. This means may include a journal surface I20 formed on a split flange I40 fastened to the upper end of the sleeve I9, and
engaged by a cooperating bore I2! formed in the upper end of cup Ii. Together these form a centering fit which maintains the members coaxial. With this arrangement, sleeve I3 must be supported so that it is free to follow lateral mo-' tion of the cup, otherwise whip and vibration which are bound to be present in the shaft would destroy the centering fit; Thus, by mounting the sleeve I9 on a yielding support, such as diaphragm I5, it is free to adjust itself to the variations in movement of the shaft, and the sealing surface of the liquid remains undisturbed.
As previously mentioned, the rotation of cup I! sets up a rotation of the mercury I8, and where this mercury I8 is in contact with another liquid, an emulsion or mixture is apt to form; and especially is this true where there is relative motion between the liquids at the surfaces of contact.
In order to avoid an area of contact between the body of liquid l8 and the well liquid 2, theiie is superimposed upon the inner surface of liquid I8 a supplemental heavy liquid 20, which is carbon tetrachloride or the like. This carbon tetrachloride layer does not form an emulsion as easily as the mercury I8. Accordingly the emulsion or mixture between the mercury I8 and the well liquid is prevented.
Surfaces in contact with the mercury I8, such as the liquid measure exterior of the casing 4; or slightly above this exterior pressure. For this purpose various arrangements have been pro- 'of the well, would have to be provided to permit replacement of the liquid filling of the casing when desired.
At the level 23 there is a pressure transfer between the fluid fllling the casing 4 and the exterior well liquid. As long as there is suflicient air, fluid or liquid within th casing 4, this surface 23 is prevented from rising to any of the rotary parts of the apparatus or to'the windings.
The prevention of emulsiflcation illustrated in Fig. 1 may be secured in somewhat different ways. In Fig. 2 the rotary shaft 24 extends out of the top 25 of the casing, which in this form may be-a rigid member. The shaft carries a rotary cup 26 in telescopic relation with the nonrotary depending sleeve-like member 27. The cup 26 has a central aperture 89 suficiently' large to provide substantial clearance around shaft 24 which passes through it and is connectedto the shaft by a flexible member .90, such as a Sylphon, which is attached to a collar 9! secured to the shaft. Thus any vibration or misalignment of the shaft is not transferred to the cup. Within the space formedin the cup 2t and the member 21, there is disposed a sealing liquid 28, which may be carbon tetrachloride or mercury, The top surface of this liquid seal 28 is in contact with well liquid through the clearance aperture 29 in the top 25. A filler pipe 30, as before, may be provided for the seal.
Whatever emulsion or mixing may occur, due to the contacting well liquid andliquid 28, is reduced by centrifugal separation. For this purpose the cup 26 is provided with radial ribs or vanes 38. During rotation of the cup 26, these vanes cause the heavier part of the mixture to be thrown radially outwardly and against the over-- lapping sealing surfaces between the members 26 and 27. The dotted line 32 indicates the surface v of the heavy liquid 28 under the influence of as of cup I1 and sleeve I9, may be appropriately treated to insure against undesirable chemical action. Furthermore, a filler pipe may be provided, both for the carbon tetrachloride 20 and v the mercury I8, indicated generally by 2|.
Provision may be made to maintain the fluid pressure within casing 4 at about the same value centrifugal force when the shaft 26 and cup 26 are rotated. The centrifugal separator action continues during periods of operation of the motor. I It causes the heavier constituents of the mixture to be separated and to be urged by centrifugal action into proper sealing relationship.
In Fig. 3 is shown a further variation of the arrangement in which there is an annular sleeve dividing the surface of the liquid seal into two portions, as well as means for guiding the cup. Thus, the shaft 24 extends through an opening 29 in the rigid top member 25, which carries an annular depending member 92 surrounding the shaft. The lower end of this member is divided to form a skirt I02 and a cylindrical guide I03.
"The rotating cup 93 includes the upper ring 94,
rotated at its usual speed. The centrifugal eparator action is the same as in the form shown n Fig. 2, and in addition, a seal such as dis- :losed in connection with Fig. l is provided. The :ealing liquid 28 is urged to better sealing relation with the rotary and non-rotary elements, by the resultant centrifugal force.
In the form of the invention illustrated in Figs. 4, 4a, 5 and 5a, the well liquid 2 is shown as disposed in the well casing I, as before. In this instance the electric motor is provided with a rotary casing 33, guided for rotation about a central stationary shaft-like member 34.
The rotary casing 33 is shown as provided with a pump operating shaft 35, appropriately fastened to the central boss 36, extending upwardly from the casing 33. This shaft 35 is shown as extending upwardly to the pump 31. The pump, it will be understood, is suspended from above in the usual manner and supports a stationary frame 38, extending downwardly so as to support a stationary spider 39. Upon this spider there is a boss 48 into which the central stationary member 34 is secured.
At the upper end of the stationary member 34 there is supported the stationary stator windings 4|. The connections for this winding, as shown, extend downwardly through the bore 42 formed centrally of the stationary member 34, and'outwardly through the bottom of the spider 38. These connections may then proceed, as by way of a water-proof cable, to the top of the well for connection to an appropriate source of power, such as the mains 43, a switch I23 being interposed to control the motor.
The rotor windings are provided on the rotor laminations 44 fastened to the inside of the casing 33. This rotor winding may be of the conventional squirrel cage type. For rotatably supporting the casing 33 upon the central non-rotary member 34, use is made of a ball bearing structure 45, the inner race of which is mounted upon the top of the member 34. Another ball bearing structure 48 is supported on a transverse apertured wall 41 formed within the casing 33.
In the present instance the upper portion of I the casing 33 is intended to be filled with some neutral fluid lighter than the well liquid. For example, oil or air may be used. Where the casing is filled with air, there is preferably a layer of oil on the water to prevent the air being absorbed in the water. Pressure balance between the inner and outer liquids is secured by leaving the bottom of the casing 33 open, the normal level of ,the contacting surfaces of the liquids being indicated at the surface 48.
Since casing 33 is rotary, rotation is imparted by its operation to the liquid filling the casing 33. There would normally be a considerable relative motion between the two liquids at the surface 48, enhancing deleterious mixing or emulsification. In order to reduce this effect, means are provided to reduce the relative motion between the liquids at the surface of contact 48. For this purpose fins or vanes or ribs 49 are disposed radially within the casing 33 and carried by the wall thereof. These vanes have a considerable depth, intersecting or passing through the plane 48. They have the effect of rotating both bodies of liquids immediately adjacent the surface of contact 48. In this way relative motion is made so insignificant as effectively to prevent material emulsification or mixing.
In this form of the invention it is necessary to insure that the contact level 48 will be maintained between the upper and lower limits of the vanes 49. For this purpose the liquid filling of oil in the casing 33 should be replenished upon undue rise of the level 48. The manner in which this is accomplished will now be de-. scribed.
A filler pipe 50 is provided, extending to the top of the well and to a source 5|, such as a reservoir, of the neutral liquid, which is maintained under suitable pressure. The lower end of this pipe 50 extends into the hollow member 34, and thence the liquid may enter by way of aperture 52into the casing 33. This flller pipe 58, however, is controlled by a valve 53, normally closed as by a spring 54, and may also be provided with a check valve I31 to prevent reverse flow of the oil. Valve 53 is adapted to be opened by a solenoid 55 whenever the circuit for this solenoid is energized. This circuit may include a step down transformer I22, having its high tension side connected to two of the power mains 43 so as to not be affected by the switch I23. The low tension side of the transformer is grounded, as by being connected to the pump housing, or a continuation thereof, by lead I24. transformer is connected tosolenoid 55 by a conductor 58. The other terminal of solenoid 55 connects to conductor 51. This conductor 51 is connected to one terminal, as I25, of' a float operated switch 58, located immediately below the bearing structure 48 within the casing 33. This float operated switch 58 is intended to close only upon an undue rise of the surface level 48. For this purpose any appropriate float mechanism may be provided. For example, the ring float 59 may be disposed around the stationary member 34 and connected through a lost motion connection 60 to operate the switch 58 upon sufficient upward movement of the float 59. The float 59 is made hollow and of such material as to be maintained substantially at the level 48 between the two liquids.
The principle of providing a rotary casing is advantageous when using an'upwardly directed shaft 35, since the shaft need not pass through the top of the casing, and thus no sealing means is required to maintain the casing fluidtight at this point.
It may be desirable to provide a gaseous atmosphere for the motor to operate in, thereby reducing friction losses. Thus, air or gas under suitable pressure may be introduced into casing 33 by a pipe BI, leading from a source I25 at the top of the well. This pipe enters bore 42 of stationary shaft 34, and communicates with the interior of the casing through opening 81. In order to prevent rapid absorption of this air or gas by contacting the well fluid, a layer 38 of neutral liquid or oil is provided. This has the surface of contact 48 with the well liquid as before, blades 48 serving to prevent emulsification at this surface. To insure the presence of the proper amount of air in the casing to maintain the upper surface I21 of this oil within the desired limits, a valv I28 is provided to control conduit BI. This valve is normally maintained closed by a spring I29, and is opened by energization of a solenoid I38 in response to the closing of afloat operated switch I36. Switch I36 is similar to switch 58 and is actuated through a lost motion connection I35 by a float I3I, arranged to float adjacent the surface I2'I of the light liquid 88,
The remaining terminal of the supported within the central One contact of this switch is grounded, the other contact I32 being connected by lead I33 to solenoid I30; lead I34 from the solenoid to transformer I22 completes-this circuit.
It will be apparent that a rise in the level of surface 48 will close switch 58, causing valve 53 to open and admit additional oil to casing 33.. The pressure of the air or gas above the upper surface I21 of this oil will be effective to maintain this surface substantially against movement, hence the added oil will depress surface 48 until the lowering of float 59 opens the switch, stopping the' flow of oil. If the upper surface I21 advances into the casing to a predetermined height within the casing 33 due to an insufficient volume of air, float I3I will close switch I36, causing valve I28 to open, admitting air to the casing. This depresses the liquid surface, permitting the float to fall, open' the switch and check the fiow of air.
It is rot necessary for the purposes of the invention to maintain the liquid surfaces and I21 within close limits, but only that the former be at a point where it will be engaged by paddles .3 and the latter at a reasonable distance below the motor. Furthermore, for additional assurance, the normal depth of the oil, between levels 48 and I32 may be sufiicient to ensure that even when all the air is inadvertently permitted to escape, the water level will never reach even as far as switches 58 and I36.
The showing of switches 58 and I36 is merely diagrammatic, as it would be desirable to provide switches capable of making and breaking the circuits abruptly. Such switches are well known and many types are on the market.
It is possible for the pump structure to be located below the rotary casing. In this conthe contacting well liquid 2.
nection, a slightly different form of seal construction may be advisable. This is illustrated I in the form of the invention shown in Fig. 6.
In this form, as before, there is a well casing I in which there is the well liquid 2. The pump is shown in more or less diagrammatic form by the bowls 62 and by one of the pump runners 63 fastened to the rotary shaft 64. The stationary parts of thepump are shown as supported at the bottom of a hollow column 65 leading to the relatively smaller pump discharge column 66.
The pump operating shaft 64 is shown in this instance asfastened by the aid of the flange 61 to the bottom of a rotary casing 68 enclosed within the hollow column 65. This rotary casing 68 is shown as supported upon a central stationary member 69. This stationary memben is supported by the aid of the flange 10 and the stand- .ard 1I to'the top flange 12 of the column 65.
The rotary supports for the casing 68 are shown as'including the ball thrust bearingstructure 13. The inner race of this structure 13 is boss 14 formed upon the transverse wall 15. Similarly, at the lower closed end of the casing 68, a ball bearing structure 16 is provided, having its outer race supported upon the upwardly extending central boss 11.
The rotor squirrel cage winding may be accommodated upon the laminations 18 supported in the casing 68. The stator windings-19 are shown as supported upon the stationary member 69. The connections 80 for the stator winding 19 are shown as extending into the recess 8I in the member 69, and thence upwardly through the cable connections 82 to the top of the well.
In the present instance, a filling 83 of relatively heavy neutral liquid is provided for the casing 68. This may be carbon tetrachloride or the like. The top 84 of the casing 68' has an aperture 85 through which the stationary shaft 69 passes. This aperture is a close fit about the shaft, but is not sealed against entry of the well liquid. The wall 15 has'a similar opening 99 for the shaft. The heavy filling may be replenished, if desired, through a filler pipe 86 extending to the T fitting 81, which accommodates the cable 82 and which is screwed into the top of the stationary member 69. In this way the heavy liquid filling can pass through the pipe 86 into the recess 8|, and thence through the radial aperture 88 into the interior of the casing 68. Since the casing is substantially filled with liquid which is heavier than the well liquid, any of the latter entering the casing through opening 85, or any emulsion formed, will remain in the chamber I00 formed between the top 84 of the casing and wall 15.
This heavy liquid is given a motion of rotation by operation of the casing 68, which tends to throw the heavy liquid outwardly, separating it from any mixture between the heavy liquid and The heavy liquid naturally settles toward the bottom of the casing and the separated well liquid rises to the top. This level of contact IOI. is intended to be normally considerably above the ball bearing structure 13.
drical guide I03, as before. The rotating cup I05 in this case includes an upper ring I06 engaging the ring also the cylindrical surface of guide I03, having an annular lip I01 engaging the'lower edge or shoulder of guide I03. This ring is sup ported on the flexible member tached to a collar I08 secured to spring IIO, confined between the lip and the collar, maintains the lip in contact with the guide. A sealing liquid 28 is provided as before. The arrangement described effectively prevents vibration of the shaft being imparted to the surface of the sealing liquid adjacent the sealing surfaces, and aids in maintaining. the effectiveness of the seal.
The modification shown in Fig. 8 differs from that of Fig. 7 in that the spring is stationary. Thus the collar II2 supporting the spring does not have an extended flange.' A ring I I3 engages the under side of lip I01. This ring is guided concentrically with guide I03 by a cylindrical surface I I4 formed in cage II5 which is supported by top 25. Ring I I3 is maintained against rotation by stationary anchor pins I I6 secured to the cage, but is free to move axially in response to spring II1, confined between 25, which carries the annular and cylinthe shaft. The flange I 09 of collar I 08 is approximately the same outside diameter as lip I01, and a compression submerged in well liquid, a casing, a body of liquid serving to exclude the well liquid from the casing, and having a surface open to the interior of a part of the casing, and means simultaneously engaging both of said liquids and interposing an resistance to relative rotation between the liq- 2. In a submersible structure adapted to be submerged in well liquid, a rotary casing, a stationary support for said casing, and a neutral liquid in the casing, and in contact with the well liquid, said casing including means retarding admixture of the liquids.
3. In a submersible structure adapted to be submerged in well liquid, a casing, a neutral liquid in the casing, and in contact with the well liquid, said neutral liquid being in contact with rotating surfaces of the structure, tending to impart rotation thereto, and means simultaneously engaging both of said liquids, whereby relative rotation between the liquids is retarded adjacent the contacting surface.
4. Ina submersible structure adapted to be submerged in well liquid, a casing, a neutral liquid in the casing, and in contact with the well liquid, said neutral liquid being in contact with rotating surfaces of the structure, tending .to impart rotation thereto, and means whereby relative rotation between the liquids is retarded adjacent the contacting surface, comprising paddle members extending across said surface.
5. In a submersible structure adapted to be submerged in well liquid, a rotary casing, a stationary support for said casing, a neutral liquid in the casing and in contact with the well liquid, and paddles carried by the casing and extending across the surface of contact between the liquids.
6. In a submersible structure adapted to be submerged in well liquid, a rotary casing having an opening at the bottom, a neutral liquid light er than well liquid'in the casing and in contact at its lower surface with the well liquid, and means carried by the casing for retarding relative motion between the two liquids at the surface of contact.
I. In a submersible structure adapted to be submerged in well liquid, a rotary casing having an opening at the bottom, a neutral liquid I P1 8. a second float lighter than well liquid in the casing and in contact at its lower surface with the well liquid, and paddles carried by the casing and extending across the surface of contact between the liquids.
8. In a submersible structure adapted to be submerged in well liquid, a rotary casing, a neutral liquid in the casing and in contact with the well liquid, the surface of contact being within the casing, and means for replenishing the neutral liquid in the casing, comprising a float switch adapted to be actuated when the surface of contact approaches a definite position, a circuit controlled by the switch, and a source of neutral liquid supply controlled by said circuit.
9. In a submersible structure adapted to be submerged in well liquid, a casing, a neutral fluid in the casing, and a layer of neutral liquid in the casing to separate the fluid from the well liquid, said layer of neutral liquid having a surface of contact with the well liquid as well as a surface of contact with said fluid, means for replenishing the neutral liquid in the easing comprising, a float switch adapted to be actuated when the surface of contact with the well liquid approaches a definite position, a circuit controlled by the switch. and a source of neutral liquid supply controlled by said circuit, and means for maintaining the surface of contact with the fluid below a deflnite point comswitch adapted to be actuated when said surface approaches said point, a circuit controlled by said second switch, and a source of fluid controlled by said last mentioned circuit.
10. In a submersible structure adapted to be submerged in well liquid, a casing, a body of fluid in the casing, and a layer of neutral liquid in the casing to separate said fluid from the well liquid, said layer of neutral liquid having a surface of contact with said well liquid, means for replenishing the neutral liquid in the casing, comprising a float switch adapted to be actuated when said surface of contact approaches a definite position, a circuit controlled by the switch, and a source of neutral liquid supply controlled by said circuit.
THOMAS G. MYERS.