US2075315A - Self-priming centrifugal pump - Google Patents

Description

March 30, 1937 E. P. TEEL v SELF PRIMING CENTRIFUGAL PUMP Filed July 17, 1935 2 Sheets-Sheet l INVENTOR Eric Z? 7626 ATTORNEYS March 30, 1937. E. P. TEEL SELF PRIMING CENTRIFUGAL PUMP Filed July 17, 1933 2 Sheets-Sheet 2 Patented Mar. 30, 1937 map STATES 2,015,315 SELF-PRmflNG ornament. rum

Eric P. Teel, Lansing,

Mich., asslgnor to Novo Engine Company, Lansing, Mich.) a corporation of Michigan Application July 1'], 1933 Serial No. 680,868-

-3 Claims.

This invention relates to pumps and'more particularly to improvements in self-priming centrifugal pumps and has as its objects to simplify, render more efiicient and improve generally de- 5 vices of this nature.

One of the important objects of this invention is to provide means for rendering the pump selfpriming in order that it may function as a suction pump to lift. liquids. To this end, a simple but effective means is provided for trapping-an amount of liquid sufilcient to initiate the operation of the pump'as a suction pump together with means for circulating this liquid through a tube and nozzle connected to the pump intake 35 to thereby induce a vacuum in the pump intake and to furthermore additionally remove the air therefrom by entraining. the same in the circulating liquid and freeing the entrained air at the discharge side of the pump.

Another object of this invention is to provide an improved means for mounting the impeller and impeller shaft wherebyi these parts may be assembled as a unit and this assembly then mounted within the pump casing whereby the impeller is properly located axially of its shaft and positioned for a correct running fit in the impeller space.

Another object of the invention is to provide an improved form of impeller designed to inespecially when considered in connection with the accompanying drawings, wherein Figure 1 is a perspective view of a self-priming pump constructed in accordance with my invention;

Figure 2 is a sectional elevational view taken substantially on the plane indicated by line 2-2 of Figure 3, looking in the direction of the ar-'- rows Figure 3 is a vertical sectional elevational view taken substantially on the plane indicated by direction of line 33 of Figure 2, looking inthe 50 the arrows;

Figure 4 is a detail sectional view taken substantially on the plane indicated by line 44 of Figure 3, looking in the direction of the arrows;

Figure 5 is a horizontal sectional view taken v 66 substantially on the plane indicated by line 55 in Figure 3, looking in the direction of the arrows, and

Figure 6 is an enlarged detail sectional view showing the priming nozzle.

Referring now more particularly to the drawings wherein like reference characters indicate like parts, it will be noted that the pump com-- prises a casing lilprovided with a suction or intake space II and a discharge space 12. The discharge space is provided with an outlet or discharge opening l3 to which a discharge pipe l 4 is connected. The intake or suction space H is provided with an inlet opening IE to which a suction. or intake pipe [6 is suitably connected.

The casing H! is provided with a hand hole I! closed by a cover 18 which may be conveniently secured in place by means of a locking lever 19 and a rod and thumb nut 20. The pump may be initially supplied with liquid through this hand hole and the hand hole also provides means for cleaning the interior of the casing and for assembling the priming tube, yet to be referred to.

The portion 2| of the wall that defines the in take or suction chamber ll defines one side of an impeller space 22 in which an impeller 23 rotates. The upper. boundary or the impeller spaceis defined by anarcuate wall 24 which is connected to the left-hand wall of the pump casing, as viewed in Figure 3; and extends transversely thereof terminating in the end 25. The end 25 of this wall 24 together with the adjacent wall of the casing l0 defines a discharge passage 26 which communicates with the discharge chamber or space l2, this discharge passage being arranged substantially tangential to the peripheral channel of the impeller chamber.

A portion 21 of the impeller space wall 24 is machined to a close running fit for the impeller 23 so as to form a seal at this point to divide the suction or intake side of the impeller from the discharge side thereof.

Beginning at the seal 21 and extending in a counter-clockwise direction is a peripheral channel or impeller space 28 of gradually increasing size, this impeller space increasing in size until it merges into the discharge passage 26 heretofore referred to. Intermediate the length of this peripheral channel or impeller space and preferably substantially one-third the distance between the seal 21 and the discharge passage 26 is a vacuum chamber 29, substantially triangular in shape as illustrated. This vacuum space or chamber 29 is located at the juncture at the end of the impeller space wall 24 and the adjacent inclined portion of the wall of the casing II and projects substantially radially from the periphery of the impeller.

The other vertical wall of the impeller space is closed by a cover 20 removably secured in place by means of bolts 3! or the like.

The impeller preferably comprises a circular plate or disk-like portion 32 provided with a plurality of arc-shaped vanes 32 extending substantially radially from a hub 34 to thus produce a plurality of outwardly opening substantially pocket-like recesses 35 open axially at one side thereof.

The impeller is mounted upon a shaft 38 which is in turn supported by bearings Iland 38 contained in a bearing housing 38. This housing also contains a plurality of seals 40 which serve the double purpose of protecting the bearings against corrosion by the liquid and also to seal the suction space against the entrance of air around the impeller shaft.

The impeller is properly located on the impeller shaft by means of spacer sleeves 4t and 42 in conjunction with the bearings 01 and 38 to thus properly locate the impeller and provide the-proper running fit with respect to the impeller space 22.

The impeller 23 is keyed onto the shaft 58 by means of a key 43 and is secured in place by means of a nut 44 provided with a cotter pin 45.

The bearing housing together with the associated parts may be mounted as a unit in the pump housing ill by locating the same in an opening 46 in the pump housing provided for that purpose, the bearing housing being secured in place by means of bolts 41.

In assembling this unit, the bearing 31 is first assembled on the impeller shaft 3Q against a shoulder 48 provided for that purpose. Then the spacer sleeve If is placed on the shaft and next the bearing 38 is positioned against the end of the spacer sleeve 4|. The spacer'sleeve 42 is then placed on the shaft I! and abuts the bearing 38, the seals being also assembled on the sleeve 42. This sub-assembly is then assembled with the bearing housing, the bearing 31 being pressed into a seat in the bearing housing and held in place by a retainer plate 49. This assembly is then mounted in the pump housing and subsequently the impeller 23 is fitted onto the end of the shaft and secured in place by the nut 44 and the cotter pin 45. Thereafter the side of the impeller space is closed by the cover plate 30. The bearing 38 is held axially on the impeller shaft between the spacers 4| and 42 but is permitted to float in the bearing housing 39.

Ihe bearings 31 and 38 may be supplied with lubricant from a lubricant receiving space 50 to which lubricant can be supplied by means of the lubricant supply opening 5|.

The suction or intake space I I communicates with the impeller space 22 by means of an opening 52 surrounding the impeller shaft 36. As has been previously described, the peripheral channel of the impeller space communicates with the discharge passage 25 which leads to the discharge chamber I2.

Communicating therewith at preferably the highest point of the suction space, as at 53, is a priming tube 54 which connects with a'priming nozzle 55 which nozzle extends through the impeller space wall 24 and into the vacuum cham ber 29. The nozzle 55 is provided with a plurality of angularly arranged apertures 56 which provide communication "between 11. d scharg chamber I! of the pump casing and the vacuum chamber 29. In the operation of the pump, during the priming period, liquid fiows downwardly through the converging apertures 55 and induces a suction in the priming tube 54 which, as previously described, is connected to the top of the intake or suction chamber ll so as to assist in exhausting the air therefrom.

The operation of the pump is as follows:

The casing is first filled with liquid preferably up to the level of the intake ll or substantially to the level indicated by the dot-and-dash line L. This liquid is introduced through the hand hole l1 and the liquid assumes a uniform level throughout the pump casing. When the pump is started, that part of the liquid surrounding the impeller 23 is thrown outwardly into the peripheral channel of the impeller space and then through the discharge passage 25 and into the discharge or outlet chamber I2. Its place is immediately filled by more liquid flowing of its own weight from the suction or intake space H through the opening 52 and into the impeller space, this continuing until the suction or intake chamber ll is entirely empty.

As a consequence, the level of the liquid in the discharge chamber I2 is raised and this liquid flows of its own weight through the openings 56 of the priming nozzle ,55, This fiow is assisted and accentuated by the action of the impeller her so thatthe air remaining in the suction or intake chamber II and in the suction pipe I8 is drawn through the priming tube l5 and this air charge chamber whereupon the air i'rees itself from the liquid and passes oil. through the discharge opening the liquid remaining" in the discharge chamber so as to be available for again being passed through the priming nozzle.

This operation is continued, the same liq id be ing repeatedLv circulated through the pump until eventually all of the air is exhausted from the suction pipe and liquid rises to take its place. When the suction pipe is filled with liquid and all of the air has passed out of the discharge the pump is fully primed and continues to operate in the same manner as the conventional type of centrifugal pump.

If the supply of liquid being pumped should fail and the level should fall below the bottom end of the suction pipe, air will enter the suction pipe instead of liquid and the liquid in the suction pipe will fall back to its source and no more will be discharged until the suction pipe is again filled. The pump can be operated continuously so that when the liquid level again rises to cover the bottompf the end of the suction pipe, the same cycle in the process of exhausting the air is repeated and the pump will again be re-primed.

When the pump is shut down, a suflicient amount of liquid is trapped in the pump so that when the pump is again started it will automatically prime itself as heretofore described.

Obvious modifications may suggest themselves to those skilled in this art, and to this end reservation is made to make such changes as may come within the purview of the accompanying claims.

What I claim as my invention is:

1. In a self-priming centrifugal pump ofthe class described, a casing having an inlet chamber, a discharge chamber, an impeller, an impeller chamber therefor having a substantially tangential discharge communicating with said discharge chamber, said impeller chamber having an enlargement forming a vacuum chamber arranged to the rear of said discharge with relation to the direction of rotation of said impeller, a priming tube connected to said inlet chamber and terminating in a nozzle connected to said vacuum chamber, and an opening through said nozzle for flowing liquid from said discharge chamber through said nozzle into said vacuum chamber,

for the purpose set forth.

2. In a pump of the character described, 9, casing, inlet and discharge chambers formed therein, an impeller arranged in a vertical plane within said casing, an impeller chamber therefor having a substantially tangential discharge passage feeding into said discharge chamber and. having a substantially radially extending compartment forming a vacuum'chamber, and means connecting said vacuum chamber to said inlet chamber and to the lower portion of said discharge chamber, as and for the purpose set forth.

3. In a pump of the class describedac'asing having an inlet chamber, a discharge chamber, an impeller, an impeller chamber therefor having a substantially tangential discharge communicating with the discharge chamber and having an enlargement forming a vacuum chamber arranged to the rear of the discharge with relation to the direction of rotation of the impeller, and a priming conduit connecting the inlet chamber and discharge 20 chamber to the vacuum chamber.

ERIC P. TEEL.

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