US2885964A - Pumps - Google Patents

Description

INVENTOR. KENNETH R. LUNG ATTORNEYS K. R. LUNG May 12, 1959 PUMPS Filed March 18, 1957 FIG-T United States Patent PUMPS Kenneth R. Lung, Dayton, Ohio, assignor to The Tait Manufacturing Company, Dayton, Ohio, at corporatom of Ohio Application March 18, 1957, Serial No. 646,693 Claims. (Cl. 103-87) This invention relates to submersible pumps.

The invention has particular relation to submersible pumps of the type including a motor as a part of the entire assembly which is submerged in a well, and with the motor depending below the pump. If such motor is of the totally enclosed type, it is necessary to provide a rotary seal at the junction of the motor shaft and the top of the motor casing where the shaft extends upwardly to the pump portion of the assembly. Pumps of this type are commonly subject to use with relatively sandy water, particularly during the initial period of use of a well, and such sand in the water constitutes a danger to the seal between the shaft and motor casing, since if the seal should be abraded sufiiciently to leak, the motor may be flooded and spoiled.

It is a primary object of the present invention to provide a rotary seal for a submersible pump which is so constructed and arranged as to minimize the possibility of damage by sand in the water handled by the pump even after extended periods of use.

An additional object of the invention is to provide such a rotary seal which is so constructed that the natural forces incident to operation thereof in use in a submersible pump assembly tend to dispel sand from access to the relatively moving sealing parts.

It is also an object of the invention to provide a rotary seal construction having the advantages outlined above which in addition can be removed and replaced with maximum ease whenever such operation is necessary or desirable.

Further objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

In the drawing- Fig. 1 is a perspective view illustrating a submersible pump assembly of the type to which the present invention relates;

Fig. 2 is an enlarged fragmentary view in axial section through the connection between the pump and motor portions of the assembly of Fig. 1, the view being a section on the line 22 of Fig. 3;

Fig. 3 is a radial section on the line 33 and Fig. 4 is a fragmentary section on the line 44 of Fig. 2.

Referring to the drawing, which illustrates a preferred embodiment of the invention, the submersible pump assembly shown in Fig. 1 includes a motor casing 10, a pump shell 11, and an intake cap 12 which connects the parts and 11 and is covered by a screen 13. The motor shaft 15 extends upwardly from the casing 10 into the interior of the cap 12 and is there connected by a coupling 16 to the pump shaft 17. Fig. 2 also shows a fragment of the impeller 18 and cover 19 of the lowermost pumping stage in casing 11, these parts being indicated as of the structure shown in my copending application Serial No. 633,412, filed January 10, 1957, and assigned to the same assignee as this application.

of Fig. 2;

The construction of the intake cap 12 and its connection to the motor casing 10 are best seen in Figs. 2 and 3. A bracket 20 forms the upper end of the motor assembly, and it is secured in sealed relation with the upper end of casing 10 as by means of screws 21 and O-ring 22. An annular shoulder 25 projects upwardly on the upper surface of bracket 22 in concentric relation with shaft 15, this relationship being established by the bearing portion 26 of bracket 20 in which shaft 15 is journaled by a bushing 27.

The shoulder 25 serves also to locate the intake cap 12 in concentric relation with the motor casing and the motor shaft 15. The base portion of cap 12 is formed as a relatively flat internal flange 30 which seats on the upper surface of bracket 20 and is provided with a concentric throughbore 31 proportioned for close fitting telescoping engagement with the shoulder 25. Bosses 32 on the upper surface of flange 30 receive screws 33 which secure the cap 12 to bracket 20, and the cutaway opening 34 in flange 30 is to receive the motor cable 35, which is provided with a sealing gland 36 where it passes through bracket 20 into the interior of motor casing 10. The flange 30 is connected with the upper portion of cap 12 by ribs 37 which are spaced angularly from each other to provide the inlet passages to the inlet chamber within cap 12.

The rotary seal assembly provided by the invention is indicated generally at 40 and is located within the intake cap 12. Referring particularly to Fig. 4, the seal includes a rotary sealing ring 41 which may be of carbon or other suitable material and is secured in sealed relation on shaft 15 as by means of a rubber sleeve 42 and clamping ring 43. The rotary sealing ring 41 engages a complementary stationary sealing ring 44 which is secured as by means of a rubber sleeve 45 in a counterbore 46 within the shoulder 25. The rings 41 and 44 are shown as maintained in sealing arrangement in the usual way, by means of spring 47, a metal sleeve 48, and back-up plate 49 held axially on shaft 15 by means of a snap ring 50 in a groove 51.

In accordance with the invention, the several parts of the seal as just described are so proportioned and arranged that the upper surface of stationary sealing ring 44 is located above the plane of the surrounding area of the shoulder 25 and flange 30. With this construction, any sand entering the interior of inlet cap 30 cannot efl'ectively reach the complementary sealing surfaces of the rings 41 and 45. Thus not only is the surface 55 higher then the surrounding surfaces so that sand does not tend to stay thereon even when the parts are at rest, but when the pump is in operation, the rotation of ring 41 and its associate parts of the seal will tend to produce outward currents which would sweep any sand off the surface 55.

If the rotary seal assembly were incorporated within the bracket 20, or otherwise located internally of motor casing 10, and if then sand should enter and reach the sealing ring 44, damage to the seal or to other parts within the casing would be most likely to occur, and this is particularly true in view of the difiiculty of eliminating such sand once it had entered. With the present invention, however, the natural forces present in the operation of the rotary seal cooperate to minimize the possibility even of access by sand to the sealing parts, and thus even further reduce the possibility of entry of sand between the sealing surfaces of the rotary and stationary ring. The possibility of abrasion of these parts is therefore most remote, but if they should need replacement, as because of natural wear, they are accessible for easy servicing upon simple removal of the screen 13 and coupling 16.

As an illustration of proportions of these parts which have been found satisfactory, with a motor casing having an overall diameter of the order of 4 inches, the shoulder 25 and flange 36 may each be inch measured axially of shaft 15, and the ring 44 may be formed of a ceramic material and may also be inch thick. With these dimensions, the rubber mounting sleeve 45 of the relative proportions shown in Fig. 4 is sufiicient to support the ring 44- with its upper surface 55 above the level of the end of shoulder 24. Furthermore, even if ring 44 were bottomed in counterbore 46, its surface 55 would still be not less than flush with shoulder 25, and this would provide equivalent advantages so long as the surface 55" is not lower than the surrounding areas to estab lish a recess where sand might collect.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the in vention which is defined in the appended claims.

What is claimed is:

1. In a submersible motor including a motor shell sealed at the lower end thereof and having a drive shaft projecting from the upper end thereof, the combination of a bracket secured in sealed relation with said upper end of said sheil and receiving said shaft therethrough, said bracket being exposed at the top thereof for direct access by liquid wherein said motor is submerged, a rotary sealing ring surrounding said shaft above said bracket, flexible means securing said ring in sealed relation with said shaft providing for limited movement of said ring on said shaft, means on said shaft biasing said ring toward said bracket, a stationary sealing ring located below said rotary sealing ring for sealing engagement between the upper surface thereof and said rotary ring under the biasing action of said biasing means, means securing said stationary ring on the upper end of said bracket, and said securing means being proportioned to support the upper surface of said stationary ring above the surrounding area of said bracket to prevent accumulation of sand therein.

2. In a submersible motor including a motor shell sealed at the lower end thereof and having a drive shaft projecting from the upper end thereof, the combination of a bracket secured in sealed relation with said upper end of said shell and receiving said shaft therethrough, said bracket being exposed at the top thereof for direct access by liquid wherein said motor is submerged, said bracket having a counterbore in the outer end thereof surrounding said shaft, a stationary sealing'ring secured within'said counterbore, a rotary sealing ring surround-- ing said shaft above said stationary ring, flexible means securing said rotary ring in sealed relation with said shaft providing for limited movement of said rotary ring on said shaft, means on said shaft biasing said rotary ring into sealing engagement with the upper surface of said stationary ring, and said stationary ring being proportioned to extend axially above the surrounding area of said bracket to prevent accumulation of sand on said upper surface thereof.

3. In a submersible motor including a motor shell sealed at the lower end thereof and having 'a drive shaft projecting from the upper end thereof, the combination of a bracket'secured in sealed relation with said upper end of said shell and receiving said shaft therethrough, said bracket being exposed at the top thereof for direct access by liquid wherein said motor is submerged, an annular shoulder projecting upwardly on said bracket above the surrounding area of said bracket in concentric relation with said shaft, a rotary sealing ring secured to said shaft above said shoulder, a stationary sealing ring secured within said shoulder, means biasing said rotary sealing ring into maintained sealing engagement with said stationary ring, and said sealing ring being proportioned to locate said upper surface thereof axially above said shoulder to prevent accumulation of sand thereon.

4. In a submersible pump assembly including a submersible motor casing having a drive shaft projecting above the upper end thereof and a pump having a driving connection with said shaft, the combination of an intake cap connecting said pump and said motor casing and defining an inlet chamber extending therebetween through which the liquid wherein said assembly is submerged fiows to said pump, a rotary sealing ring secured on said shaft for rotation therewith within said inlet chamber in facing relation with said motor casing, a stationary sealing ring for engagement by said rotary ring, means mounting said stationary ring on the upper end of said motor casing within said inlet chamber, means biasing said rotary sealing ring into maintained sealing engagement with the upper surface of said stationary ring, and said stationary ring and said mounting means therefor being proportioned to maintain said upper surface of said stationary ring above the surrounding area of said casing end to prevent accumulation of sand on said ring surface.

5. In a submersible pump assembly including a submersible motor casing having a drive shaft projecting above the upper end thereof and a pump having a driving connection with said shaft, the combination of an intake cap connecting said pump and said motor casing and defining an inlet chamber extending therebetween through which the liquid wherein said assembly is submerged fiows to said pump, a bracket forming the upper end of said casing, a flange on the lower end of said intake cap seated on said bracket and having a central throughbore, an annular shoulder extending upwardly on said bracket in concentric relation with said shaft and projecting through said bore in said flange to locate said cap and said casing in coaxial relation, a rotary sealing ring secured on said shaft within said inlet chamber and above said shoulder, a stationary sealing ring for engagement by said rotary ring, means securing said stationary ring within said shoulder and with the upper surface thereof extending above the surrounding area of said shoulder and said flange to prevent accumulation of sand on said surface thereof, and means biasing said rotary ring into maintained sealing engagement with said upper surface of said stationary ring.

References Cited in the file of this patent UNITED STATES PATENTS 2,268,218 Lurn Dec. 30, 1941 2,577,559 Armstrong et al. Dec. 4, 1951. 2,668,068 Bredemeier Feb. 2, 1954 2,682,229 Luenberger June 29, 1954 2,722,892 French Nov. 8, 1955 2,766,696 Lung Oct. 11, 1956 2,786,952 Pleuger Mar. 26, 1957 FOREIGN PATENTS 434,505 Great Britain Sept. 3, 1935

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