US3011446A

US3011446A - Submerged motor pump structure

Info

Publication number: US3011446A
Application number: US800611A
Authority: US
Inventors: George N Tsiguloff
Original assignee: Tokheim Corp
Current assignee: Tokheim Corp
Priority date: 1956-02-17
Filing date: 1959-01-21
Publication date: 1961-12-05
Anticipated expiration: 1978-12-05

Description

Dec. 5, 1961 G. N. TslGULoFF SUBMERGED MoToR PUMP- STRUCTURE Original Filed Feb. 17, 1956 (1:1 EIN! INVENTOR 'foar: N. 73160105 www arentY This invention relates to a submerged motor-pump. A

More specifically it relates to a unitary motor-pump of the kind which is entirely submerged in a liquid, such as gasoline, contained in a tank and is suspended on the discharge pipe which is connected to the upper end of the unit. The discharge pipe is connected by a header to one or more delivery lines which are in turn connected to one or more dispensing pedestals. Each pedestal includes a switch which is capable of energizing or deenergizing a starter to start or stop the motor of the unit. Each pedestal also includes control valves, a meter, a register etc. which enable the operator to control and` measure the ow of liquid through the pedestal.

A system of the type discussed above is disclosed in the Patent Number 2,812,111, granted November l5, 1957 to Wright, Clymer and Jackson and further explanation of the system is not believed necessary for an understanding of the invention disclosed herein. The instant application is a division of my copending application Serial Number 566,112 tiled February 17, 1956 for Submerged Motor Pump, now Patent No. 2,921,532.

A further object of the invention is to provide a multistage pump which has a body made up of a number of annular sections which are held in axial alignment by means of a sleeve or shell.

Yet another object of the invention is to provide a pump impeller of light, cast metal which includes a hub insert to yield maximum keyway strength while minimizing the size of the keyway.

These and other objects will become apparent from a study of this specification and the drawings which are attached hereto, made a part hereof and in which:

FIGURE l is a vertical elevation of the pump-motor unit with parts shown in section to show the construction.

FIGURE 2 is a plan view of view of the mounting wedge.

FIGURE 3 is a vertical sectional view of the impeller showing the insert and the keyway.

FIGURE 4 is a bottom plan view of the pump cover and anti-vortex vanes.

General construction Referring first to FIGURE-L tbe numeral 1 represents the electric motorrwhich is fitted at its upper end with a cap 3 which receives the Aelectric conduit 5, and at the lower end with an end bell 7 through which passes the motor shaft 9. An axially directed, annular ange' 11 enters a groove 13 in the Yimpeller 15 to restrict the flow of liquid into the space17 between the bell and the impeller. This space also communicates with a channel 19 which opens into the tank to prevent the accumulation of pressure in the space which would produce an undesirable downward thrust on the impeller.

Unit supporting means Referring again to the upper end of the motor, a discharge litting 21 is attached to the motor by screws 23.

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ternally pipe tapped bore 31 which receives the discharge pipe 33.

The face 35 of the fitting is provided with a circle of tapped holes 37. A pair of semi-circular, complementary wedges 39 (FIGURE 2) are provided with an external tapered surface 41 which matches the bore 27 and with a cylindrical bore 43 which receives the discharge pipe 33. The pipe 33 is threaded and screwed into the bore 31 and thereafter the wedges are inserted in the bore 27. A ring 47 which tits around the pipe is provided with holes 49 which are disposed to align with holes 37, and the ring is installed above the wedges and drawn down thereagainst by screws 51 which enter holes 37 and 49. As the ring is drawn down the wedges move inwardly to grip the pipe. The frictional engagement afforded by the wedges transfers part of the weight of the motor pump unit to the pipe above the threads which do not, by themselves, have suihcient strength to safely support the weight of the unit.

Diffuser and mpeller structure It will be seen from FIGURES l and 2 that the impellers 15 which may be one or more in number in accordance with the service requirements, are rotatively driven by shaft 9 through the usual Woodrul type keys 53.

Because the motor-pump unit may have to be installed in a tank through existingstandard ilanges, it is necessary l to maintain the diameter of the unit at a minimum. Since the inner and outer diameters of the impeller throats 55 greatly aiect the performance of the pumps, the outer diameter of the hub of the impeller must be minimized. At the same time the impellers are usually made of metals having low shear stress value.v Further the hub cannot be extended in length without considerable expense and waste of materials. Accordingly, it will oe seen that diculty is encountered in providing adequate bearing for the keys.

To overcome this diiculty, the impellers, as shown in FIGURE 3 are provided with an insert of steel 57 into which the keyway 59 is cut. 'Ille insert is provided with an exterior radial ange 61 which enters the web portion 63 of the impeller so as to provide greater bonding area and also to prevent any possible axial separation of the bearing from the impeller.

As shown in FIGURE 1, the impellers are held on the shaft by the screw 65. The pump casing comprises'a diffuser ring 67 and a pump cover 69 which are generally of annular shape. t The diuser is centralized with respect to the end bell 7 by means of a rabbet joint 71. The cover 69 abuts the bottom of the diuser and both pieces are held on the motor by screws 73.

The pump shell or sleeve 74 is a cylindrical tube which tits over the lower end of itting 21 and is prevented from upward motion by a flange 16 on the tting. Downward motion of the shell is prevented by a ilange 75 on the pump cover. The shell fits the tting, bell, diiuser and cover very closely so that it serves to align the cover and diffuser very closely. v The .shell is radially spaced from the motor so that the liquid discharged from the pump as at 77 passes between the motor and shell to the discharge pipe.

A radial pin 78 in the cover enters a notch 80in the sleeve to prevent rotation of the sleeve.

The shell is also provided with a port 82 which is held aligned with the conduit 19 by the pin '78.

The pump lcover has a radially inwardly extending ange 79 which terminates in a central inlet opening or eye 81. An annular axially extending groove 83 in the cover which receives an axial flange 85 of the lowermost impeller serves to prevent backllow of discharge liquid to the inlet of the impeller.

Also formed on the pump cover, as shown in FIGURE 4, are a number of axially extending radially disposed vanes 87. Six of such vanes are shown although more or fewer may be used. The vanes terminate short of the opening 81 and the outer periphery of the cover.

A cylindrical screen or strainer 89 is fitted to and surroundsvthe varies and is centralized by them. Alternate vanes have cylindrical outer edges 91 which are drilled and tapped as at 93 to receive screws 95. A bottom plate 97 is held against the bottoms of the vanes by the screws. The plate is formed with a central, raised, dome like protuberance 99 which extends a distance approximately equal to half the height of a rib toward the opening 81.

The form of the protuberance, when a radial cross section is considered, is in the shape of an ogee curve having a large radius adjacent the cap and a small radius at the apex of the protuberance. This provides a smooth, regular curve for the liquid to follow in moving to the eye of the impeller.

The varies dampen the swirling action which is set up adjacent the impeller while the protuberance occupies the space in which a vortex would normally form. This structure effectively prevents the formation of a vortex and consequently prevents the impellers from becoming gas bound.

Operation When the motor l is energized, the shaft 9 and impellers 15 are rotated, liquid is drawn from the tank through the screen 89, through the space between the vanes 87, through the opening 81 and into the eye and throat 55 of the lower impeller from which it is thrown radially outwardly and is thence drawn back through the diffuser to the eye of the second impeller which discharges the fluid outwardly to the discharge passage 77.

From this passage the liquid flows upwardly between the motor and shell and out through the discharge fitting and pipe 33, through the header and delivery line to the pedestals.

As stated above, the wedges 39 transfer the weight of the motor-pump unit to the discharge pipe above the threads to prevent excessive loading of the threaded portion of the pipe. The shell holds the motor, diffuser and pump cover in good alignment while the pin 78 keeps the shell from rotating and keeps port 82 aligned with channel 19 so that liquid may escape from the space 17 to the tank to prevent undue thrust from being applied to the upper impeller.

The screen 89 prevents foreign matter from entering the pump and the vanes 87 and protuberance 99 as well as plate 97 prevent the formation of a vortex within the screen and prevent the entrance of gas into the pump which would impair or possibly stop the operation of the pump.

The source of gas may be the liquid itself which is gasied by turbulence. The vanes and plate assist in preventing such turbulence by conducting the liquid in a smooth stream to the opening 31.

It is obvious that various changes may be made in the form, structure and arrangement of parts of the specific embodiments of the invention disclosed herein for purposes of illustration, without departing from the spirit of the invention. Accordingly, applicant does not desire to be limited to such specific embodiments but desires protection falling fairly within the scope of the appended claims.

I claim:

1.. A submersible motor-pump unit comprising an electric motor having a discharge iitting mounted at one end, an end bell mounted at the other end and a rotary shaft extending through the bell, impeller means mounted on the shaft, a pump body comprising a number of substantially cylindrical elements mounted end to end on said bell to enclose said impeller means, means for holding said elements against rotation relative to said bell, a cylindrical sleeve, axially spaced, generally ycylindrical guide means extending radially from said motor and concentric with said irnpeller means for guiding said sleeve, said sleeve extending in radially spaced relation with respect to said motor and over said elements, said elements being formed to closely t in said sleeve for alignment thereby with each other and with said impeller means.

2. The structure defined by claim l wherein said end bell denes a pressure relief channel, said sleeve defines a port disposed to align with said channel and wherein means are provided which engage said sleeve and one of said elements to prevent rotation of said sleeve to disalign the port and channel.

3. The structure defined by claim l wherein said fitting is provided with one of said cylindrical guide means.

4. The structure defined by claim l wherein said fitting is provided with one of said cylindrical guide means and said end bell is provided with another of said cylindrical guide means.

5. A submersible motor-pump unit comprising an electric motor having a discharge fitting mounted at one end, an end bell mounted at the other end and a rotary shaft extending through the bell, impeller means mounted on the shaft, a pump body comprising a number of substantially cylindrical elements mounted end to end on said bell to enclose said impeller means, means for holding said elements against rotation relative to said bell, a cylindrical sleeve, axially spaced, generally cylindrical guide means extending radially from said motor and concentric with said impeller means for guiding said sleeve, said sleeve extending in radially spaced relation with respect to said motor and over said elements, said elements being formed to closely fit in said sleeve for alignment thereby with each other and with said impeller means, keying means mounted in said shaftV for driving said impeller means, said impeller means being of metal having a low shear strength and having hubs of small radial thickness because of the design requirements of said unit, the improvement Which comprises providing an insert of metal having a high shear strength cast integrally within said hub, said insert defining a bore adapted to receive said shaft and defining a keyway of minimum depth.

References Cited in the le of this patent UNITED STATES PATENTS 1,872,111 Bricken Aug. 16, 1932 2,033,833 Kent Mar. l0, 1936 2,492,141 Gaylord Dec. 27, 1949 2,506,827 Goodner May 9, 1950 2,519,473 Jack et al. Aug. 22, 1950 2,612,843 Gruetjen Oct. 7, 1952 2,689,529 Wightman Sept. 2l, 1954 2,812,111 Wright et al. Nov. 5, 1957 2,857,849 Pezzillo Oct. 28, 1958