US1920484A - Rotary pump - Google Patents

Description

Aug. 1, 1933. w o. SIEMEN El AL 1,920,484

ROTARY PUMP Filed May 7, 1930 Fig. 6.

I jA/VENTORS Fatented Aug. 1,.1933- STATES ROTARY Pm Otto Siemcn and Johannes Hinsch, Itzehoe,

Application May 7, 1930 Serial No. 456,516, and

} in Italy May 27, 1929 5 Claims. (on. its-es) The present inventionrelates to rotary pumps of the type in which a vaned impeller wheel rotates in a surrounding casing and the pumping action is obtained by escape of an auxiliary a pumping liquid from the pockets between the vanes, thereby forming a vacuum which draws a fluid being pumped into the pockets, and the subsequent return of the pumping liquid into the pockets, thereby creating a pressure on' the to fluid being pumped to force the latter fluid through an outlet.

Rotary pumps of this type have been constructed in which the impeller is eccentric to the surrounding chamber thereby forming a passage outside the periphery of the wheel, and varying in width between the tips of the vanes and the casing; in this type of pump the pumping or aux iliary liquid is caused to leave the pockets between the vanes by centrifugal force at the wide part of the passage and is forced back into the pockets at the narrow part of the passage. Because of the friction and energy losses the efficiency of a pump of this construction is quite low. Another construction which has been in use provides a rotor in the form of 1 a vaned wheel enclosed in a neatly fitting casing, one or each side wall of which is formed with a segmental channel, one end of which communicates with an induction and the other with an exhaust port. The pump and the suction pipe must be primed with water which, owing to frictional contact with the wheel, is caused to flow through the. channel from the induction to the exhaust'port. ,Gaseous fluidscannot be pumped through a device of this type since it is impossible to build up a satisfactory pressure difierential between the inlet and exhaust ports.

The principal objects of the present invention are to produce a-pump .of this type which will pump gases as readily as liquids, and which pro--' vides a pressure head much higher than has been previously obtained in similar pumps, and the invention consists in arranging the inlet and exing channel, near the opposite ends thereof and between the channel and the axis of rotation of the wheel or rotor, so that a liquid circulating with the vanes through the casing will, by its the channel construction.

haust ports separately from a segmental pump-.

Fig. 3 is another cross section of the pump taken in an opposite direction to that of Fig. 1', parts of the rotor being broken away to show the channel construction.

Fig. 4 is a view of the rotor.

Fig. 5 is a development of the channels.

Fig. 6 is a cross-section through the channel and the wheel pockets, showing diagrammatically the. flow of water. I

Like reference characters refer to like parts in the different figures.

The pump comprises a rotor in the form of a vaned wheel or rotor, having a substantially circular hub and radial vanes, the wheel being enclosed concentrically in a neatly fitting casing which may be formed in two 'halves a and 2) secured together in any desired manner. In the casing walls at opposite sides of the rotor, arcuate identical segmental pumping channels (1 and f are formed, the outer radius of the channels being substantially equal to the radius. of the impeller wheel, which extend about the axis of rotation 01' the wheel from and to a point where the vanes move in an upward direction, the ends of the channels being spaced from each other. The channels are open only towards the rotor throughout their lengthand are gradually reduced in depth at both ends to merge with the casing wall as shown in Fig. 5, thereby providing a cross-section gradually increasing or diminishing in area to cause the pumping liquid to be gradually withdrawn or returned to the pockets between the blades, as will be later pointed out. The channels, are coextensive, so that corresponding ends are opposite each other and the openings in the channels (2 and f are arranged on opposite sides of the tips of the vanes so that the sides of the outer portions of the vanes pass over the openings in the channels; the channels are so arranged as slightly to approach the axis of the rotor in the direction of rotation, that is, the channels are nearer the rotor axis'at the point where the liquid is discharged from the channel into the pgckets of the impeller than at the point where the liquid flows into the channels from the impeller pockets. This results in a lowered centrifugal force so that, as the liquid reenters the pockets,-the energy losses betwen the wheel and the pumping liquid will be substantially diminished.

An intake port e is arranged parallel to and adjacent that end ofthe channel d into which the liquid first flows from the impeller pockets.

The port e is arranged between the end of the channel and the axis of rotation of the rotor and opens into the pockets adjacent the hub of the rotor. At the end remote from the tapering end of channel d, the intake port is arranged to provide a channel which becomes less deep in the direction of rotation of the impeller to merge with the side of the casing as shown in Fig. 1; this channel construction causes the fluid being pumped to be swept along by the vanes and gradually directed into the pockets. The port is connected in any desired manner through the casing to the intake of the pump.

An exhaust port g is arranged on the opposite side of the impeller, parallel to and adjacent the end of the channel f which is remote from the intake port e, that is, adjacent the end of the channel which directsfthe pumping liquid back into the pockets of the impeller. This port g is arranged between the channel f and the axis of rotation of the impeller and opens to the impeller pockets adjacent the hub; the port is connected through the casing in any desired manner with the exhaust outlet of the pump as shown in Fig. 2. This port, at the end remote fromthe end of the channel I, is provided with a channel which diminishes in area in a direction opposite to the direction of rotation of the impeller to merge gradually with the side of the casing.

In operation the pump casing is primed with a pumping liquid. With the rotor- 0 moving in the direction of the arrow, the pumping liquid will be urged by centrifugal force against the circumferential inner surface of the casing. Considering now an impeller pocket on the impeller wheel in a position in which there is no communication between the pocket and any channel,-

that is, a'pocket as at h (Fig. 3) and rotating in the direction indicated; as the pocket approaches the openings of the channels d and f and the inlet opening 6 and passes along where the channels are gradually becoming larger in area, the pumping liquid is gradually carried outwardly by centrifugal force into the channels, forming a vacuum in the portion of the pocket adjacent the hub and thereby drawing the fluid being pumped into the pocket through the inlet opening e which is now in communication with the base portion of the pocket. As the pocket continues its rotary movement, the inlet opening is closed and the fluid being pumped is carried within the pocket until a position is reached in which the exhaust port is in communication with the pocket. In this position, the channels at and j are in area, and thereby force the pumping fluid into the pocket and force the fluid being pumped out through the exhaust port. The same pumping action occurs with relation to each individual pocket so that the action is uniform. The construction of the pump makes it equally adapted for pumping gases or liquids or a mixture of the two as above pointed out an i be apparent that, in pumping a liquid, the ling...

gagement with the periphery of the casing to C.

This movement of the water produces at A a lower pressure than exists at D and a circular current is produced as shown by the arrows. To this circular motion is added the rotary motion of the wheel which imparts to the water a rather high velocity; the latter is partially converted into pressure in the lateral channels, part of the water reentering the wheel at D with a reduced speed and receiving an additional impulse from the wheel. The result is a helical movement of the water through the wheel pockets and the side channels and every complete loop of the helix transmits a certain amount of energy from the wheel to the water comparable to the individual stage of a multi-stage pump.

We claim:

1. A rotary pump comprising a vaned rotor, and an enclosing casing forming a neat fit with said rotor, the side walls of said casing being formed with segmental channels carried about the axis of rotation of the rotor so as to be swept by the tips of the vanes and forming nearly a complete circle, the channels being open towards the wheel and gradually reduced in depth to nothing at the ends, the casing having an induction port arranged so as to be swept by the root portions of the vanes where the latter move in an upward direction and in the neighbourhood of one end of said channels, and an exhaust port arranged so as to be swept by the root portions of the vanes beneath the axis of rotation and in the neighbourhood of the other end of the channels.

2. A rotary pump comprising'a rotor having impeller vanes defining pockets thereon, a cas ing concentrically enclosing said rotor, a substantially'annular segmental channel in the side wall of said casing substantially concentric to the axis of the rotor and adjacent the outer periphery of the rotor, said channel being open throughout the length thereof only to the pockets in the rotor, and inlet and outlet ports arranged adjacent opposite ends of said channel and between the ends of said channels and the hub of the rotor, said channel increasing in area adjacent the inlet port and decreasing in area adjacent the outlet port in the direction of rotation of the rotor, said ports being separated from said channel and being open to the pockets of the rotor, whereby an auxiliary pumping fluid, which is adapted alternately to exhaust from the pockets between the vanes on the rotor and enter said channel and to be returned to said pockets from the channel, is not exhausted through said outlet port.

3. A rotary pump-comprising a casing, a vaned impeller concentrically mounted therein, said vanes defining pockets therebetween, a circumferential channel in the casing adjacent the outer ends of the vanes, said channel being open throughout its length toward the pockets in the impeller and varying in cross-section, an intake port between said channel and the axis of the impeller in substantially parallel relation to a portion of the channel which is increasing in cross-sectional area, and an exhaust port in substantially parallel relation to a portion of the being formed with a segmental channel to ing nearly a complete circle substantially concentric to the axis of the rotor and open throughout its length to the pockets in the rotor and adjacent the periphery of said rotor, with the radius of the channel decreasing in the direction of rotation of the rotor, and intake and exhaust ports in substantially parallel relation to the opposite ends'ot the channel and spaced therefrom between the ends of the channel and the axis of the rotor, said channel increasing in area adjacent the inlet port and decreasing in area adjacent the outlet port in the direction of rotation o! the rotor, both said ports being open to the pockets in the rotor, whereby an auxiliary pumping fluid which is adapted alternately to be discharged from and returned to said pock ets is prevented from'discharging through said outlet port.

- 5. A rotary pump comprising a rotor having impeller vanes thereon, said vanes defining pockets therebetween in the periphery. oi. said rotor,

creasing in area adjacent the outlet port in the direction of rotation of the rotor, said ports being separated from said channel and opening to the pocketsin said rotonsaid intake port having a channel extending therefrom open throughout its length to the pockets in the rotor and diminishing in, cross-section in the direction of rotation of the rotor.

. OTTO SIEMEN.

JOHANNES HINSCH.

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