US2358744A - Centrifugal pump - Google Patents

Description

Patented Sept. 19, 1944 UNITED j STATES PATENT orrlcsf canrnrruoar. PUMP Alexey J. S tepanofl', Phillipsburg, N. 1., assignor to Ingersoll-Rand Company, New York, N. Y a corporation of New Jersey Application September 6, 1943, Serial No. 501,377-

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accomparwing this specification and ,in which similar reference numerals refer to similar parts,

Figures 1 and 2 are longitudinal elevations, partly broken away, of a centrifugal pump constructed in accordance with the. practice of the invention and showing the impeller sections ad- Justed to different positions to provide effective blade areas of different proportions, and

Figure 3 is a side elevation of the pump im peller.

Referring more particularly to the drawing,

the pump designated, in general, by comprises a casing 2| and a shaft 22 extending horizontally therethrough.

The casing 2| is recessed to provide a pumping chamber 23 for the accommodation. of an impeller 24. of the double-suction type, arranged upon the shaft 22. The casing also has a discharge opening 25 for the pumping chamber and inlet channels 26 that lead to the ends of the pumping chamber.

In accordance with the practice of the invention, the impeller ,24 consists of two, preferably identical, sections 21-23 that are adjustable relatively to each other endwise of the shaft in order to vary the impelling efiect of the impeller and thus the capacity of the pump. Each impeller section comprises a shroud 28 having an integral annular flange 30 that encircles the shaft 22 to receive liquid from the inlet channels 28.

On the peripheral surfaces of the flanges 30 are wearing rings 3| that cooperate with the inner surfaces of rings 32 to limit leakage of liquid from the pumping chamber along the outer surface of the impeller .in the direction of the.

inlet channels. v

' Each impeller section has a hub 33 of frustoconical shape connected to the associated shroud 23 by blades 34 and 35 on the opposed surfaces of the sections 21-23, respectively. The opposed surfaces of the flared ends of the hubs 33 cons'titute seating surfaces 33 that engage each other to limit movement of the impeller sections toward each other. a v

The seating surfaces 33 lie between the shrouds and the free radial edges 31' of the blades so that these portions of adjacent blades 34 and 35 may overlap each other in varying degrees, accordingly as the impeller sections are shifted toward 6 or away from each other.

Preferably, only one impeller section, in the I present instance that designated 2], is secured against relative rotation upon the shaft, and the hub 33 of said impeller section 21 is accordingly 10 provided with a key slot 38 for slidable engagement with a key 39 seated in the shaft 22. The impeller section 28, on the other hand, may be free to rotate upon the shaft within the limits permitted by the blades 34 of the impeller seclfi'tion 21 and is rotated in' unison with the impeller section-21 through the overlapping portions of the blades.

Individual adjusting means 40 for controlling the positions of theimpeller sections with re 20 spect to each other are disposed upon the shaft 22 and project from the ends of thecasing 2| so that they may be readily accessible for adthe hubs 33, said ends being constantly held against the seating surfaces. by a spring 43 in- 35 terposed between shaft 22. v

The spring 43 thus also tends to constantly slide the sleeves ll outwardly along the shaft, and such movement of the impeller sections and the sleeves is limited by collars 41 threadedly connected to the shaft for adjustment longitudinally in flxed position upon the shaft.

A sealing member 49 in the outer endof the sleeve ll encircles the shaft 22 and is compressed by the collar 4'! for preventing leakage of liquid alo'ng the surface of the shaft to the exterior of the pump.

In the operation of the device, whenever it is 50 collars 4'! are rotated either toward each other or away from each other to decrease or increase the overlapping areas of the blades 34 and 33 and thereby decrease or increase the effective or actlve'area of the impeller blades. Thus, if it be the hubs 33 and encircling the thereof and having set screws 48 to lock'them desired to vary the capacity, of the pump, the

' The spring a will, in the various positions the the inner ends of the sleeves ll under all conditions of operation.

I claim: 7' o A centrifugal pump, comprising a casing, a shaft in the casing, a double suction impeller on the shaft comprising a pair of half-sections having blades on their opposed surfaces in overlapcollars may occupy upon the shaft, maintain the Y hubs 83 seated firmly against the seating surfaces ll and the sleeves 4| in the correct position with respect to the collars '41, it being under. stood that the spring 48 is capable of exerting suillcient force against the impeller sections to move these parts readily along the shaft in the directions of the collars 41. This force will, moreover, be augmented by the pressure of the liquid within the impeller and the impeller sec-- tions will, therefore, always be held firmly against ping relation with each other, hubsoi' frustoconical shape on the half-sections slidable endwise of the shaft, seating surfaces on the flared ends of the hubs cooperating with each other to limit sliding movement of the halfssections toward each other, sleeves on the shaft adjustable longitudinallyof theshaft and relatively to the half-sections and having end portions to serve as abutments for the outer ends of the hubs. and a spring interposed between the inner ends of the hubs for pressing the hubs against the sleeves.

APEXEY J. STEPANOFF.

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