US 3716309 A
A motor and pump unit adapted for submerged operations in a body of liquid such as gasoline comprises a cylindrical tube having mounted therein a hermetically sealed motor which is operatively associated with a pump unit disposed at the lower end of the tube. The diameter of the motor is less than the inside diameter of the tube whereby fluid pumped by the pumping unit passes through the annular passageway defined between the motor and the tube, and is conveyed to the conventional piping system of a gasoline dispensing unit. The motor is contained in a fully sealed housing with a lip seal being provided about the drive shaft of the motor to prevent gasoline from entering the motor.
Description (OCR text may contain errors)
United States Patent [1 1 Mitchell 1 Feb. 13, 1973 SUBIVIERSIBLE MOTOR AND PUMP Hllllil Primary Examiner-C. J. Husar Attorney-Thomas M. Marshall [5 7] ABSTRACT A motor and pump unit adapted for submerged operations in a body of liquid such as gasoline comprises a cylindrical tube having mounted therein a hermetically sealed motor which is operatively associated with a pump unit disposed at the lower end of the tube. The diameter of the motor is less than the inside diameter of the tube whereby fluid pumped by the pumping unit passes through the annular passageway defined between the motor and the tube, and is conveyed to the conventional piping system of a gasoline dispensing unit. The motor is contained in a fully sealed housing with a lip seal being provided about the drive shaft of the motor to prevent gasoline from entering the motor.
5 Claims, 6 Drawing Figures all SUBMERSIBLE MOTOR AND PUMP UNIT The present invention relates to fluid dispensing apparatus, and more particularly to what is known commonly as a submersible motor and pump unit which is connected by suitable piping to liquid dispensers, such as gasoline dispensers for use in well-known type service station installations.
The tank source of supply, normally underground, ordinarily is remotely positioned from the dispensers, and the submersible motor and pump unit is positioned in the tank source of supply, the inlet end of the submersible motor and pump unit being spaced a small distance from the bottom of the tank to prevent the pumping of any water or foreign matter which may accumulate in the tank source of supply.
The present invention relates to a novel submersible motor and pump unit,'and more particularly a submersible motor and pump unit which includes a hermetically sealed stator and rotor construction which is maintained in a dry condition, rather than having the gasoline flow through the stator cavity, or having the stator filled with inert material and then sealed, as is the common practice in submersible motor and pump units known heretofore. The primary problem involved with motor constructions wherein an inert material is filled in the stator cavity is the difficulty in maintaining the seal about the motor in order to keep the system in operation. On the other hand, in those motor and pump units wherein the product gasoline is allowed to flow through the stator cavity, a problem may arise caused by the abrasive effects of the foreign materials passing through the unit and causing premature bearing failure as well as scouring the insulation material on the wires of the motor.
Accordingly, it is an object of this invention to provide a more efficient and reliable submersible motor and pump unit than known heretofore.
It is a further object to provide a submersible motor and pump unit including a tubular casing having axially mounted therein a hermetically sealed motor of smaller diameter than the inside diameter of said casing, thereby said motor and said tubular casing define a passageway for the pressurized fluid leaving a pump connected to said motor and disposed at the inlet end of said tubular casing.
It is still a further object of this invention to provide a submersible motor and pump unit as hereinabove described including a lip seal surrounding the drive shaft extending from the motor to the pump.
These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:
FIG. 1 is a diagrammatic view showing an underground tank provided with a submersible motor and pumpunit, and the piping from the outlet of said pumping unit assembly to individual gasoline dispensers located at ground level or above;
FIG. 2 is a vertical sectional view, partly in elevation, taken along line 2-2 in FIG. 3, of the submersible motor and pump unit of the subject invention;
FIG. 3 is a view taken along line 3-3 in FIG. 2;
FIG. 4 is a view taken along line 4--4 in FIG. 2;
FIG. 5 is a view taken along line 55 in FIG. 2; and
FIG. 6 is a partial sectional view of the lip seal disposed about the motor shaft of the submersible motor and pump unit of the subject invention.
Referring to FIG. 1, a gasoline dispensing system includes an underground storage tank I in which is disposed the submersible motor and pump unit 2 of the subject invention. Unit 2 is connected by suitable piping 3 to a valve manifold assembly indicated generally at 4, from which additional piping, indicated generally at 5, extends to the several gasoline dispensing pedestals 6. Also at the valve manifold 4, the electrical conduit 7, from the motor pump unit 2 separates from the liquid piping 3 and extends to the control switches in the dispenser and then to the electrical supply at the electrical power panel. (not shown) Turning to FIGS. 2 through 5, the submersible motor and pump unit 2 generally comprises a cylindrical tube 10 having an inlet end 11 and outlet end 12, and having mounted therein a hermetically sealed motor 13 and a pump 14, with an annular conduit or by-pass passageway 15 communicating the pump with the outlet 12.
Cylindrical tube 10 is of a constant diameter and includes a central shell 20 and annular end support members 21, 22, disposed at opposite ends of the shell. The outlet 12 is connected to the upper support member 21 by screws 24, and includes a bell-shaped head 30 having an internally threaded aperture 31 for connection to the piping 3 of the gasoline dispensing system. The bell-shaped head 30 is formed with an axially extending annular conduit 32 which communicates with the aperture 31 and is configured to conform with and connect to the by-passageway l5, defined by the cylindrical tube 10, to be more fully described hereinafter.
Centrally mounted within the head 30 is the female part 34 of a multiple-pin quick disconnect electrical plug 33 from which leads 36 extend to the control system of the gasoline dispensing system. The upper end of head 30 is internally threaded to accept the liquid tight electrical conduit 7 and conduct the wires 36 to the valve manifold 4 and separate it from the gasoline to piping 3. The male part 35 of plug 33 is mounted in the upper support member 21 of the tube 10, from which leads 37 extend to the motor 13.
The motor 13 is contained in a hermetically sealed housing 40 comprising a cylindrical sleeve 41 which is of a smaller diameter than the inside diameter of the cylindrical tube 10, and is connected at its ends by an upper closure 42 and a lower closure 43. Suitable O- ring seals 44 and 45 are provided between the cylindrical sleeve 41 and the end closures 42, 43 thereby defining a sealed motor housing. The motor 13 is centrally disposed within the motor housing 40 and is of conventional construction, having a drive shaft 50 extending in alignment with the longitudinal axis of the cylindrical tube 10. The motor drive shaft is mounted by means of suitable bearings and 61, and retaining rings 62 and 63 respectively disposed in closures 42 and 43, with the drive shaft extending beyond the motor housing 40 and material which will give good service when exposed to gasoline. The element 73 is centrally located in and sealed to the shell 71 in slot 72 by the mechanical pressure against the inner shell 76. The inside diameter of element 73 is smaller than the outside diameter of the shaft 50. The surface 74 of the inside diameter of the seal when installed on the shaft 50 is formed in the shape of a cone to form a line or a helix so that as the shaft rotates within the seal, there is a resulting force applied to the mating surface of the shaft which urges any liquid or foreign matter to the outside and then, of course, liquid pressure being applied to the outside effects the conventional mechanical seal which is normally available in the standard lip seal construction.
The annular support members 21 and 22 of the cylindrical tube are secured by means of elongated studs 80, and each annular support member includes an annular passageway which is configured to conform with the passageway so as to provide a continuous conduit from the pump 14 to the outlet 12 of the submersible motor and pump unit.
Pump 14 is secured to the lower annular support member 22 by studs 81, and comprises a plurality of stages including diffusers 82 and impellers 83. The latter are rotatably mounted on the drive shaft of motor 13, and mounted at the lower end of the pump 14 is an intake body 90 connected to the pump by studs 91, and including an end plate 92 and a filter screen or strainer 93.
In operation, the submersible motor and pump unit is actuated upon the passage of an electrical signal to motor 13 to actuate pump 14 whereby gasoline is drawn through the strainer 93 and thence through the impeller and diffuser sections of the pump, after which the pressurized gasoline is passed around the hermetically sealed motor 13 and through the annular bypassageway 15 leading to the outlet end 12 of unit 2. In that the motor is hermetically sealed, no gasoline enters the motor unit.
In the event that the lip seal 70 should fail whereby a certain amount of gasoline is allowed to enter the hermetically sealed housing of motor 13, the lip seal would still be effective to prevent foreign materials from entering the internal construction of motor 13 and having no adverse effect upon the bearings and stator windings. In addition, bearings 60 and 61 are coated with a suitable lubricant which would not be affected by the presence of gasoline, and the stator windings are preferably encapsulated with a suitable epoxy so as also not to be affected'by gasoline.
Another feature of the subject invention is the provision of conventional ball bearings instead of sleeve bearings as is commonly found in motor and pump units of the wet or inert-filled" types. With the subject submersible motor and pump unit it is possible to replace the ball bearings and rebuild a motor which has failed because of worn bearings. On the other hand, it is not economically feasible to salvage the rotor of a sleeve bearing motor.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalence of the appended claims.
What is claimed is: l. A submersible motor and pump unit adapted for use in a gasoline dispensing system comprising:
a cylindrical tube;
a motor assembly, including a motor having an output shaft mounted in a cylindrically shaped sealed enclosure, with the motor shaft extending from the enclosure and the diameter of the enclosure being less than the inner diameter of said cylindrical tube, said motor shaft being sealed to said enclosure by means of a flexible lip seal secured to the motor enclosure, said lip seal including a discshaped flexible sealing element having a central annular aperture through which said shaft extends, the diameter of said aperture being less than the diameter of the shaft such that as the shaft rotates a helical line contact seal is achieved in such manner as to prevent foreign materials from entering the internal construction of the motor assembly;
means cooperating within the tube as a guide for supporting said motor assembly in the tube, with the motor shaft substantially coaxial with the tube, so as to define a passageway between said motor assembly and the inner surface of the tube;
a pump connected to said motor assembly, and including a housing;
means cooperating with said pump as a guide for supporting said pump in and substantially proximate to the end of the tube; and
said pump housing defining a relatively large opening therein whereby liquid from a body of liquid in which the unit is immersed may be admitted to the submerged pump and motor unit and pumped by the pump past the lip seal, through the passageway between said motor assembly and the inner surface of the tube, and thence to the gasoline dispensing system.
2. A submersible motor and pump unit as in claim 1 in which the opposite end of the tube is of reduced diameter and is adapted to be connected to a delivery pipe leading to the gasoline dispensing system.
3. A' submersible motor and pump unit as in claim 1 wherein the opening in the pump housing includes a strainer.
4. A submersible motor and pump unit as in claim 1 wherein the pump includes a plurality of diffusers and impellers.
5. A submersible motor and pump unit as in claim 1 in which electrical means extending from the gasoline dispensing unit are connected to the sealed motor through means of a multiple contact disconnect.