US 2423436 A
Description (OCR text may contain errors)
1 July 8, 1947.
C. J. BLOM I SUBHERSIBLE HOTORIUIP Filed March 30 1945 20 2 H z z I 1% \flw J 1/ 1 v 4 Z 5 4M I 7 0. fl n. H 9 E: I M 2 2 H j Patented July 8, 1947 UNITED STAT ES PATENT OFFICE SUBMERSIBLE MOTORPUMP Carl J. Blom, San Marino, Calif., assignor to Byron Jackson 00., Vernon, Calif., a corporation of Delaware Application March 30, 1945, Serial No. 585,685
6 Claims. (01. 103 87) pumped whether the fluid be liquid, gas,- or air,'
said fluid, however, being excluded from the interior of the motor.
An object of the present invention is to Provide a submersible motorpump wherein the motor is filled with a dielectric fluid, usually liquid which may have some lubrication qualities, and incorporates means whereby the pressure of such dielectric fluid is maintained approximately equal to the discharge pressure of the associated pump.
A further object of the present invention is to provide a submersible motorpump which incorporates a. dielectric fluid filled sealing compartment isolating the motor unit from the pump unit,. and simple but effective means of maintaining the pressure therein approximately equal to the discharge pressure of the pump unit and therefore approximately equal to the pressure in said motor unit. I
A still further object of this invention is to provide a submersible motor pump which, by reason of dependable control of the relative pressures in the motor unit seal chamber and discharge side of the pump, permits use of a simple yet effective type of pump shaft seal of the mechanical type as distinguished from the liquid type, so that the motor pump may operate in any position. An example of the mechanical type of seal is shown in the U. S. Patent No. 2,002,913, issued May 28, 1935, to Mendenhall and Van Horn. An example of a liquid seal may be seen in U. S. Patent No. 2,002,914, issued May 2-3, 1935, to Mendenhall and Van Horn.
With the above and other objects in view, reference is directed to the accompanying drawings, in which: I v
Fig, l is a substantially diagrammatical view of one form of submersible electric motorpump embodying my invention.
Fig. 2 is an enlarged fragmentary sectional View of the mechanical fluid seal means employed in my electric motor pump, the view being taken substantially through 2-2 of Fig. 1.
My motor pump is encased in a cylindrical outer shell I, the upper end of which is threaded into a continuing outer shell 2 of an adapter structure 3 which, in turn is secured to a pipe line or hose (not shown) Supported within the adapter structure 3 is a motor head compartment 4 which is spaced from the outer shell 2 of the adapter to form fluid passages 5, One portion with the exterior of the adapter structure 3 and is here provided with a suitable terminal ele ment 6.
The upper end of the motor head compartment 4 4 is provided 'at its upper end with a relatively large opening in which fits a cylindrical bellows 1 having corrugated walls. The bellows extends into the motor head compartment and is adapted to expand and contract to reduce and increase the effective volume of the motor head compartment. The outer or socket side of the bellows I is covered by a flexible liner 8, preferably formed of rubber or synthetic rubber. A perforated guard plate 9 fits over the bellows 'l.
A motor casing lil issecured to the lower end of the motor head compartment 4. The motor casing is preferably double-walled, that is, it comprises an inner and outer wall defining circulation passages H.
An electric motor unit 12 is contained in the casing l0 and drives a shaft l3 the upper end of which is journaled in a bearing l4 positioned in the lower end of the motor head compartment. Incorporated in the upper end of the shaft I3 is a small fluid circulating pump l5 designed to cause flow of fluid in and around the armature and field coils of the motor, and through the passages I I. The passages II as well as one side of the circulating pump, communicate with the motor head compartment 4.
It is intended that the motor and the motor head compartment be completely filled with dielectric fluid which serves not only to insulate the parts of the motor, but also to cool the same and to lubricate the bearings.
The lower end of the motor casing I0 is joined to the upper end of a seal chamber housing IS, in the upper end of which is set a bearing I! for the shaft l3.
The shaft I3 extends through the seal chamber housing l6 through upper and lower fixed seal collars I8. Within the seal chamber housing 16 the shaft I3 is provided with rotating seal collars IS. The sets of collars I8 and I9 have flat mating faces 20. The fixed seal collars -l8 fit loosely on the shaft l3, whereas the rotating seal collars are provided with packing glands 2|. In addition, the rotating seal collars [9 are urged axially on the shaft l3 by means of springs 22 which are positioned between the packing glands 2| and abutment collars 23' secured to the shaft i3.
The seal chamber housing I6 is provided with a bellows 2'4 similar to the bellows I, but prefof the motor head compartment communicates erably of smaller capacity. The bellows 24 is and rotating collars l8 and located in one of the side walls of the seal chamber housing, and is provided with a liner 25 on its outer or socket side, and covered by a perforated cover plate 26.-
The seal chamber housing 16 may be integral with a mounting annulus 21 spaced therefrom by webs 28. Pump dischargepassages 29 are formed between the seal chamber housing 16 and the mounting annulus. These passages continue upwardly between the motor casing l and outer seal communicating with the fluid passages 5.
The under side of the seal chamber housing It and the annulus 21 define a pump chamber 29 in which is mounted a pump impeller 30 secured on the shaft l3.
A low pressure chamber 3| is formed between the impeller 30 and the under side of the seal chamber housing l6, so that the lower seal means between the shaft and the interior of the seal chamber housing l is at all times exposed to the intake or low pressure side of the pump. The lowpressure chamber [3 is maintained at the intake pump pressure by reason of a port 32. An intake cage 33 covers the annulus 21 and supports a pump bearing 34 into which extends the lower end of the shaft [3.
The mounting annulus 2'! may be hollow and communicate with the seal chamber housing to provide additional fluid capacity. A filler pipe 35 extends from the annulus 21 into the intake cage 33 for the purpose of filling the mounting annulus and seal chamber housing with a dielectric fluid, preferably identical with the fluid contained in the motor and motor head compartment.
By reason of the fact that both of the bellows I and 24 are exposed to the discharge pressure of the pump, they tend within the limits of their movements, to maintain equal the fluid pressure in the seal chamber and the motor chamber. Practically, however, the pressure in the motor chamber may be slightly less than that in the seal chamber, due to the pressure drop between the bellows 24 and the bellows 'I along the pump discharge passage; but in any event the pressure, insofar as operation of the bellows is concerned,
' need not rise in the motor compartment above that in the seal chamber formed by the seal housing I6.
If, however, any predetermined pressure differential is desired, or if it is desired to maintain the pressure in the seal compartment or the motor compartment, or both, above that of the discharge pressure of the pump, the bellows themselves, may exert a spring force, or be provided with auxiliary springs to exert a predetermined pressure in excess of the fluid pressure applied from the pump discharge passage. Conversely, a slightly lower pressure may be maintained in either or both the motor and seal compartments, by causing the spring pressure of the bellows to be exerted in the opposite direction.
The shaft sea] means provided by the fixed is are such that as long as the pressure in the seal chamber exceeds that in the motor compartment, or the pressure existing in the low pressure chamber 3|, the seals are maintained closed. If the pressure in the motor compartment should exceed that in the seal chamber by a predetermined amount as determined by the springs 22, the upper seal means may-open and permit transfer of dielectric fluid from the motor compartment to the seal compartment. This, however, cannot occur until the bellows 24 has expanded its maximum amount.
The capacities of the bellows 24 and 1 are such as to permit the normal expansion and contraction of the dielectric fluid as it is heated during operation and cooled between operations. The capacity of the bellows 'I may be large enough to permit a predetermined loss of dielectric fluid from the motor compartment into the seal compartment, to compensate for any loss from the seal compartment which may occur.
. By reason of the bellows and their relationship to the motor and seal compartments, and the use or type of mechanical seal herein described, it is obvious that the motorpump may be mounted in any position, although preferably it is located with the pump unit at its lower end.
Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.
1. A submersible motor pump, comprising: an inner shell structure defining isolated and fluid filled motor and sealing compartments; an electric motor in said motor compartment; an outer shell structure around said inner shell and defining a passageway for pumped fluid; a pump unit within said outer shell and at the sealing compartment end of said inner shell including an impeller adapted to deliver fluid to said passageway, a shaft for said impeller extending therefrom through said sealing compartment to said motor compartment; sealing means for said shaft to maintain the isolation of said sealing compartment; and expansible and contractible membranes set in the walls of said sealing and motor compartments, said membranes maintaining a sealbetween said compartments and said passageways, but transmitting to the fluid within said compartments the pressure of the fluid in said passageways.
2. A submersible motorpump, comprising: a motor unit; a pump unit; a shaft connecting said units; a shell housing said motor unit and defining a sealing chamber between said units throu h which extends said shaft; sealing means for said shaft to isolate said sealing chamber from said motor unit and said pump unit; pump discharge conduit means employing said shell as a wall thereof and communicating with said pump unit; a dielectric liquid filling said motor unit and sealing chamber; and bellows in said motor unit and said sealing chamber and exposed to the fluid pressure in said conduit means to subject the dielectric liquid in said motor unit and sealing chamber to the pressure in said conduit means.
3. In a motor pump wherein a motor unit is in a fluid-filled sealed motor compartment separated from a pump unit by a fluid-filled sealing compartment through which extends a drive shaft, the combination of: mechanical seal elements surrounding said shaft and located to separate said sealing compartment from said motor compartment and from said pump unit, the seal element between said sealing compartment and motor compartment positionedto open for admission of dielectric fluid into said sealing compartment when the pressure in said seal chamber falls a predetermined amount below the pressure in said motor compartment; bellows units for each compartment, one side of each bellows exposed to the pressure in its corresponding compartment, the other side thereof exposed to the discharge pressure of said pump unit, said bellows tending within their volumetric capacity limits, to maintain the pressures in said compartments equal.
ment between said sealing compartment and motor compartment opens to admit fluid from said motor compartment.
5. In a motor pump wherein a motor unit is in a fluid-filled sealed motor compartment separated from a pump unit by a fluid-filled sealing compartment through which extends a drive shaft, the combination of: a first mechanical seal element for said shaft between said sealing compartment and said motor compartment arranged to open to admit fluid to said sealing compartment from said motor compartment when the pressure in said motor compartment exceeds the pressure in said sealing compart ment by a predetermined value; a second mechanical seal element for said shaft between said sealing compartment and said pump unit exposed to the intake pressure of said pump unit; bellows units for each compartment, one side of each 6 bellows exposed to the pressure in its correspondin; compartment. the other side thereof exposed to the discharge pressure of said pump unit, said bellows tending thereby to maintain the pressures in said compartments equal.
6. A construction as set forth in claim 5, wherein the sealing compartment bellows unit has a lesser capacity than the motor compartment bellows, whereby upon lowering of the volume of fluid in said sealing compartment below the compensating capacity of its bellows. said first mechanical seal element opens to admit fluid from said motor compartment.
CARL J. BLOM.
REFERENCES clrnn The following references are of record in the file of this patent: