US1654907A - Centrifugal pump - Google Patents

Description

Jan. 3, 1928.

A. B. WOOD CENTRIFUGAL PUMP Filed sept. s, 1925 INVENTOR wat f5. M

A TTORNEYS .Patented dan. E3, '1928.

raiser .ALBERT B. WOOD, OF NEW ORLEANS, LOUISIANA.

CENTRIIE'UGAL PUMP.

Application led September 5, 1925. Serial No. 54,595.

This invention relates to the balancing of pump inipellers and is particularly useful in connection with centrifugal pumps,

@ne of the primary objects of my invention is to balance the pump in an improved,

simple-and edective manner.

Other objects and advantages will appear' hereinafter in the specification of the preferred form of my invention illustrated in lo the accompanying drawings, wherein:

Fig. 1 is across section of the pump and Fig. 2 is a plan section of the -pump impeller vtaken-on the line 2-2 of Fig. 1.

Referring now to the drawings it will be l5 seen that the pump comprises in general a pump casing A, an impeller and an impeller shaft C, having its bearing at 7 1n the pump casing A.'

A central inlet opening 8 is provided in the casing which constitutes the .suction inlet of the pump, thru which fluid is drawn by the impeller'and delivered to the circumferential discharge or volute 9 of the casing.

For conveniencein manufacture and as# sembling the pump casing A is made of several parts in this instance an inlet member 8a, an outlet member 9a, and a bearing member 7a.

rIlie impeller B is an enclosed impeller that is to say it consists of two walls or discs 10 and 11 spaced apart and connectedby a plurality of impeller blades lor vanes 12. 12 iii this instance two being shown.

rEhe fluid enters the impeller at 13 andis impelled by the blades 12, 12 into the circumferential discharge 9. The blades or vanes 12, 12 extend from a point. 14 adJacent the uid entrance 13 `to a point 15 on the circumference of the impeller, said blades diminishing from a considerable thickness at 14 to but little at the periphery at 15 and being suitably curved to efectively impel the duid and foreign substance through the pump with increasing velocity as it enters the chamber or outlet 9. It will be seen that the inner edges 16 of the blades 12, 12 are rounded as are the points of con-.

nection to the walis or discs 10 and 11 thus preventing to a great extent the lodging of' foreign substances at these points.

It is further pointed out that the passages 17, 1'? thru which the fluid is impelled increase in width toward the circumference of the impeiler,'the minimum width approximating the size of the fluid entrance 13.

This further prevents lodgment of foreign substances in the pump and the pump will pass anything that will enter the inlet, making it very useful for draining swamps andH the like.

Owing to the clearances between the pump impeller B and the casing A at the points 18, 19 and 20, Huid leaks past these points into the clearance spaces 21 and 22 which without provision to the contrary would cause unbalanced strains on the impeller in van axial direction because of different pressure conditions in the spaces 21 and 22. In order to prevent such unbalancing I have provided the passages 23, 23 extending thru the discs 10 and 11and blades 12, 12 whereby the fluid on either side of theimpeller is in communication thus equalizing the` pressure and consequently balancing the impeller.

It will be seen that by this arrangement the pressure on the discs 10 and 11 is equa1- ized without wasting fluid or requiring its repumpage, thus improving the eiiiciency of the pump; The life of the pump is also materially increased because the amount of fluid and foreign substance entering the space v21 through v`the clearance point 18 is very much reduced whereby the consequent wear at the point 18 on the disc 10 and the part 7a is much reduced.

Itis to be observed that by employing impeller blades constructed in accordance with my invention I am enabled to conveniently locate the balancing passages 23, 23 in the thick portion of the blades, thus avoiding the necessity of providing bridges from disc to disc for said passages which would defeat. the general purpose of this pump which is to combine eiiiciency with ability to pass anything which will enter the inlet.

In some instances it may well be that a single balancing passage 23 would suiiice.

1. In a pump, the combination of a casing having a central inlet and circumferential outlet, an limpeller within the casing comprisingA spaced discs and a plurality of impeller blades connecting said discs, a pump shaft on the end of which the impeller is carried whereby the inlet is unobstructed, there being a spacenbetween each end face of theimpeller and the casing, clearance spaces between the impelier and the casing communicating with said end `spaces whereby impelled fluid enters said end spaces, and a port extending through a blade and Connecting said end spaces, said port being located at the inner end of the blade and close to the inlet. A

2. In a pump, the combination of a casing having a central inlet and circumferential outlet, an impeller within the casing comprising spaced discs and a plurality of impeller blades connecting said discs, a pump shaft on the end of which the impeller is carried whereby the inlet is unobstructed, the passages formed by the blades being of such size 'as will pass anything which will enter the inlet, there being a space between each end face of the impeller and the casing, and clearance spaces between the impeller and the casing communicating with said end spaces whereby impelled fluids enters the end spaces, and a ort extending through a blade and connecting said end spaces, said porty being in close proximity to the entrance edge of the blade.

vided with forward ends whichl are thick.

and rounded andwwith rear ends occupying but little of the periphei of the im eller,

a shaft on theend of whlch the'impe ler'is" carried whereby the inlet is unobstructed, a space between each end face of the impeller and the casing, clearance spaces between the impeller and the casing communicating with the end spaces whereby impelled liuid enters` the latter, and a port extendin through the thick end of each blade in sustantiallparallelism 'with the axis of the shaft and connectin'g the end spaces.

In testimony whereof, I have hereunto signed my name.

' ALBERT B. WOOD.

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