US1611004A - Rotary pump - Google Patents

Description

Dec. 14 1926.

W. l. DERRICK ROTARY PUMP Filed May 4, 1922 3 L w n I m M r w. w I w 6 1 i J F 0 w 2 r! 'P ientlibe 14, 1926.

WILLIAM I. DERRICK, OF DAVENPORT,

IOWA, ASSIGNOR TO WESTCO-CHIPPEWA PUMP COMPANY, OF DAVENPORT,-IOWA, A CORPORATION OF DELAWARE.

ROTARY PUMP.

Application filed May 4,

This invention relates to rotary pumps, and more particularly to theclass of pumps employing a rotor in a housing.

An object of this invention 18 to provlde a pump with a rotor which, when the pump is operating and building up pressure, Wlll' automatically balance itself axially so that it will not bear on the casing and conse uently will reduce Wear and lengthen the life of the pump.

In' pumps of the type wherein a rotor engages water in an annular passage the rotor has a more or less close working fit between portions of the opposite walls of the casing in which it is mounted, which is necessary to cut off any substantial communication between the annular passage and the central portion of the chamber formed by the casing walls. A small amount of liquid, however, will Work through between the'rotor and side walls, and if, due to imperfect fit, a greater amount of liquid escapes to the center of the chamber on one side of the rotor than the other, an excess pressure is built up upon that side tending to push the rotor still farther toward one wall of the faces have a relatively large contact, so that accurate ositioning of the casing walls and rotor wit respect to each other is possible. Other objects will be apparent from the 1 following description in connection with the annexed drawings.

In said annexed drawings, Figure 1 is an elevation partially broken away to show a portion of the rotor and casing in section.v

Fig. 2 is a central transverse vertical section showing the cover detached.

Fig. 3 is a view of the rotor. Fig. 4: is a section on an axial plane through the rotor.

Fig. 5 is a side elevation of the casing.

tion.

1922. Serial No. 558,452.

Fig. 6 is an enlarged view of that portion pjf the rotor and casing shown in section in- Referring to the drawing, the casing body 1., base 2, and shaft supporting bracket? are cast integrally. The casing 1 is saucer shaped and has a peripheral rim 4. having a flat peripheral side face 5, an internal peripheral channel 6, the outer wall of which may be formed by an inwardly extending rib 7 having a cylindrical inner edge. The web portion of the casing body has upon the inner face thereof a relatively low annular rib 8 concentric with the rim 4:. The casing body 1 has an axial integral tubular boss 9 on the outer side thereof. The bracket 3 has a threaded bearing aperture 10 in axial alinement with the boss 9. The casing cover 11 has its inner face circumferentially rabbeted to provide a. cylindrical shoulder 12 to fit within the cylindrical inner edge of the rib 7, and a flat inner peripheral portion 13 outside the shoulder 12 to fit against the flat face 5 of the casing body 1. The contiguous faces 5 and 13 of the casing body and cover may be provided with registermg grooves preferably greater in one dimensioncross sectionally than the other, thus forming an annular packing chamber 14 to receive an annular packing member 25. The member 25 is preferably circular in cross section but may be of any desired cross sectional shape, it being necessary only that the cross sectional dimension of the packing in the direction of the axis of the pump be slightly larger than the cross sectional dimension of the chamber 1 1 in the same direc- It will thus be seen that when the cover is tightly fitted to the casing body the packing tightly engages both the cover and the casing body and may be compressed and deformed throughout the length of the chamber 14, thus insuring a tight engagement between the packing and casing and cover throughout the circumference of the packing. By having the clamber 14 of greater dimension in one direc ion cross sectionally, room is provided to contain the deformed packing so that the contiguous faces 5 and 13 of the cover and pump body may be insured of a metal to metal contact, thus insuring also an accurate fitting of the easing walls with respect to the rotor. Concentric with the shoulder 12, the cover 11 I in the web 19 of the rotor.

abutment to the inlet.

has upon its'inner face a relatively low annular rib 15 of the same diameter as the opposed rib 8 of the casing body.

By way of example the rotor casing herein disclosed is one having ribs between which the rotor has ,a close working fit and rotates. It is to be understood, however, that the ribs may be mounted upon the rotor and thewalls of the casing be straight, so that in eifect there is produced an outer annular water passage, in which the water is engaged by. the blades or buckets of a rotor. Working fit between the rotating member and the casing, otherwise relatively high pressures cannot be built up in such passage, for it would short circuit from the discharge or pressure end of the passage directly to the suction or inlet end of the passage. However, the clearance between the rotor and the casing may be varied somewhat depending upon the conditions and purposes of the pump. The preferred construction is that herein shown, in which the ribs are mounted on the casing walls and the rotor has a portion engaging between the ribs, for in this case the rotor which is the moving part has less weight and also has less surface to be engaged by the pressure of the water in the fluid channel, and conse quently less pressure is transmitted to the bearings.

A shaft 16 is journaled axially in the casing body and cover and in bearing members mounted in the tubular boss 9 and in the aperture 10 in the bracket 3. A rotor 17 is fixed to the shaft 16 within the casing. The rotor 17 is a circular disk having a hub 18, a web 19 and an outer thickened peripheral portion 20 upon the outer edges of which are formed the impeller teeth 21. Relatively large apertures 22 are formed The thickened portion 20 of the rotor has a close working fit between the annular ribs 8. and 15 of the casing body 1 and cover 11 whereby the peripheral portion of the casing-is substantially cut off from the central portion thereof. The outlet and inlet connections communicate with the peripheral portion of the casing and an abutment 23 between the inlet and outlet closes the passage outside the periphery of the rotor between the inlet and outlet and has a close fit over the rotor outside the ribs 8 and 15. The abutment is thick enough to fitover a plurality of the peripheral teeth of the rotor, whereby pressure generated at the discharge outlet cannot be released by escape of water past the A slight clearance between the ribs 8 and 15 and the rotor 12 is necessary to permit rotation of the rotor; this-slight clearance will be sufiicient even with the closest working fit to permit a relatively slight leakage to the center of the There must be a relatively close casing in the form of a thin film of liquid which acts as a lubricant between the surfaces of the rotor and ribs. The clearance may be varied in the diilerent sides and designs of'pumps for various purposes but it is desirable to equalize whatever pressures are created on the sides of the rotor to prevent the rotor from being forced axially in one direction or the other. If there is a slight misahnement betweenthe rotor and casing, a greater leakage will occur on one side of the rotor than-the other, which would tend to buildup a pressure on. he side where the leakage is greater, which increase the misalinement. By providing the large apertures 22 in the web the pressure is equalized on the opposite sides of the thatto make the channel relatively small,

as disclosed herein, a considerably higher ould tend to pressure can beproduced with my pump and still a good volume of water can be delivered.

Furthermore, it is to be understood that the particular forms of apparatus shown and described, and the particular procedure set forth, are presented for the purposes of.

explanation and illustration, and that various modifications of said apparatus and procedure can be made Without de arting from my invention, as designed in t e appended claims.

hat I claim is:

1. In a rotary pump acasing, a shaft mounted in said casing for rotary movement therein and carrying a rotor, an outer annular passage formed in said casing by said rotor and thecasing walls, bladeson said rotor engaging the water in said outer annular passage, said passage conforming in cross sectional shape to the cross sectional shape of the periphery of the rotor and having its walls disposed relatively close to the rotor, said rotor having a material part of its web portion cut away to permit flow of water from one side to the other to equalize the pressure on opposite sides thereof.

2. In a rotary pump a casing, a shaft mounted to rotate in the'casing walls, a rotor carried by said shaft, said rotor comprising a disk having a web portion and blades around the periphery, annular ribs extending from the walls of the casing on each side of the rotor and forming together with the rotor an outer annular water passage, said passage being relatively small and having inlet and discharge ports and a partition between said ports, said rotor having perforawater to pass freely, from one sideto the other when the rotor is rotating- I 3; In a rotary pump a casing forming a rotor chamber, of a rotor. mounted in said casing, said rotor having a shorter diameter than said chamber, the side walls of said casing having opposed annular ribs in close engagement with opposite sides of said rotor adjacent the periphery thereof, whereby a peripheral passage for liquid is formed circumferentially of said rotor, the walls of said passage being relatively close to the peripheral faces and edge of said rotor and substantially parallel'therewith, said ribs coact ing with said rotor to prevent any substantial leakage from said outer passage to the central portion of said chamber, said rotor, having a substantial part of its web within said'ribs removed to permit ready flow of liquid from one side of the rotor to the other to equalize the pressure on opposite sides of said rotor.

4. In a rotary pump, the combination with a casing having a shallow cylindrical rotor chamber therein, said chamber bein closed except for peripheral inlet. and outlet passages, of a disk rotor in said casing, said rotor bein of shorter diameter, than said chamber, t e side walls of said chamber having inwardly extending annular ribs in close toward the periphery thereof, whereby a pcripheral passage is formed which is substantially closed from thecentral portion of said casing, said side walls of said'chamber being tions of suflicient size in its web to ..perinit l engagementiwith opposite faces of said disk" disposed relatively closeto the-faces of the rotor, said disk having a substantial portion of-lts body within said annular ribs cut away to permit ready flow of liquid from one side of the rotor to the other to equalize the pressure on opposite sides of said rotor.' 5. In a rotary pump, a narrow cylindrical rotor chamber, a disk rotor therein having peripheral blades and being of less diameter than said chamber, the sidewalls of said chamber having annular ribs'of less diameter than the rotor between which said rotor has a close ,workin fit, whereby a circumferem.

tial assa'ge is tormed at the .outer periphery of t e chamber, inlet and outlet conduits communicating with said circumferential considerably reater than the cross sectional area ofthe circumferential passage insaid rotor chamber.

In testimony whereof, I hereunto aifix my signature.

" j L'DERltIGK,

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