US2275679A - Submersible pump and electric motor - Google Patents

Description

March 10, 1942. Y T. G. MYERS ETAL 2,275,679

SUBMERSIBLE PUMP AND ELECTRIC MOTOR Original Filed Feb. 27, 1932 INVENTORS Thomas G, M ers /4 Frank Mason BY 26 A ATTORNEY Patented Mar. 10, 1942 SUBMERSIBLE PUMP AND ELECTRIC MOTOR Thomas G. Myers, Los Angeles, Calif, and Frank Mason, Chicago, Ill., assignors to U. S. Electricai Motors, Inc., a corporation of California Original application February 27, 1932, Serial No. 595,590. Divided and this application August 23, 1937, Serial N0. 160,481

3 Claims.

This invention relates to deep well pumps, and especially to submersible electric motors for operating such pumps.

This application is a. division of an application filed in the names of Thomas G. Myers and Frank Mason for Submersible pump motor, February 27, 1932, Serial No. 595,590.

It is common to pump liquid from a deep well, such as an oil or a water well, by submerging a pump and a motor in the well. This necessitates careful sealing of the motor casing to prevent ingress of the liquid being pumped, to the motor, as otherwise the motor windings or other parts will be injured.

It has been suggested to obviate the necessity of such sealing and at the same time to prevent the well liquid reaching the motor, by supporting the motor in the top of a bell-like structure, the bottom only of which is open. When such a structure is submerged, the air trapped therein is compressed and serves to prevent the liquid from reaching the motor.

Due to the slightporosity of the materials used, and other causes, as for instance thosev incident to theoperation of the motor, this trapped air may be lost slowly from the bell. It is accordingly an object of this invention to provide means for replenishing the air surrounding the motor.

Another object of this invention is the provision of means whereby the liquid discharged by the pump is effective to replenish the air surrounding the motor.

This invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawing accompanying and forming part. of the present specification. This form will now be described indetail, 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 this invention is best defined by the appended claims.

Referring to the drawing, the single figure is a diagrammatic sectional view showing a pump and motor in operative position in a well, with means for replenishing the gaseous atmosphere which surrounds the motor.

In the drawing, there is shown, by way of example, a well casing i, from which a l quid 2, usually water, or a mixture of water and other substances, is to be pumped out. Suspended in the well is a pumping unit 3 attached to the lower end of the discharge pipe 4. The pumping unit includes a pump 5 which is usually of the centrifugal type, and an electric motor 6 for operating it. The motor is operatively connected to the pump by means of shaft I and is sup: ported in the upper part of a long tubular housing I. This housing is closed at its upper end by a cover 9, but is open to freely admit the well liquid at its lower end ill. The length of housing 8 is so proportioned with respect to the depth to which it is to be submerged, that the air trapped within it will be of sutllcient volume when compressed by the well liquid to maintain the fluid level II below the motor.

To ensure the volume of this trapped air being maintained sufliciently large to keep the fluid level II below the motor, means are provided for adding additional quantities of air to it. Thus the horizontal branch I! of the discharge pipe can be provided with a small pipe or tube It leading back into the well and opening inside the lower end of easing 8, as indicated at II. This tube is so arranged that a small portion of the liquid from the pump is returned to the well, and as it enters the pipe, it entrains air which is liberated in-the motor housing.

'Ijo effect this result, pipe l3 has an enlarged portion I! where it connects to the discharge pipe II. This enlarged portion is joined to pipe I! by a conical section it, serving as a nozzle.

A short piece of pipe i1 extends across pipe l2, and is open to the atmosphere on top, the other end opening into the nozzle. The water passing the end of pipe I! as it enters the nozzle draws air through the pipe and traps or entrains it, in the manner of an ejector. The mixture of air and water then flows downward in pipe l3 and is discharged under the bell II. The entrained air then rises to the surface ll of the liquid in the bell and escapes from the liquid into the space occupied by the motor.

To obviate'the necessity of a running seal or stumng box where shaft I passes out of casing 8, the following construction is employed. A tube l8 surrounding shaft 1 is fixed in the top 9 of casing 8 and extends substantially to the lower end of the casing. This formsan annular are supplied with current from a source outside the well bymeans of a waterproof cable, not

shown. Shaft 20 is rotatably supported by bearings 24 and 25 suitably supported in casing l and provided with lubricating means. Either of these bearings may be arranged to act as a thrust bearing to support the shaft and rotor. Shaft 20 extends downwardly to the bottom of the casing, where it is connected to the pump shaft 1 in any convenient manner as by a threaded coupling member 26.

Brief consideration will show that the well liquid is free to enter the top of tube l8, flow downwardly in the space between this tube and shaft I, and thence upwardly in the space between tube l8 and the hollow shaft 20. However, the

trapped air in the casing 8 will be eflective to check the rise of liquid in the space between tube l8 and hollow shaft 20, and maintain the surface of the liquid in this space at the same height as liquid surface ll.

What is claimed is:

1. In a submersible pump structure, a housing adopted to be submerged in the liquid to be pumped and open at the bottom, a power unit in the housing, a pump operated by the unit, a discharge pipe for the pump, and extending upwardly out of said liquid, means for returning a part of the liquid from the pipe, to the lower mosphere at the upper part of the housing for the power unit.

2. In a submersible pump structure, a housing adapted to be submerged in the liquid to be pumped and open at the bottom, a power unit in the housing, a pump operated by the unit, a discharge pipe for the pump, and extending upwardly out of said liquid, a tube connecting the upper portion of the discharge pipe with the lower part of the housing to return a part of the pumped liquid to the housing, and means to entrain air with the liquid as it enters said tube.

3. In combination with a structure adapted to be submerged in a well, and including a pump, a discharge pipe for the pump and a motor for operating the pump, the motor being positioned in the upper part of a relatively long housing open only at the bottom, whereby air trapped in the housing by the well liquid is effective to keep said liquid out of the motor, means to supply air to said housing including a nozzle near the top of the well and aranged to be supplied with liquid from said pipe, a conection to said nozzle whereby air is entrained by the liquid passing through the nozzle, and a conduit connecting the outlet of said nozzle with said housing.

THOMAS G. MYERS. FRANK MASON.

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