US2064635A - Rotary type pump - Google Patents

Description

t Dec. i5, i936, B. B. STERN ROTARY TYPE PUMP Filed Jan. l5, 1936 45 Sheets-Sheet 1 Dec.15,1936. BB. STERN 2,064,635

` l I ROTARY TYPE PUMP Filed Jan. l5, 1936 3 Sheets-Sheet 2y j 'HSE'.

for.' Jell/anun Kfer,

. QS, B E, STERN V 064,53

l ROTARY TYYE PUMP Filed dan. 1s, 193e 3 sheets-sheet s UNITE l non' Y E PUB/IP Benjamin B. Stern, Chicago, Application January is, i936, serial No. 58,788

4 Claims.

In the old types of pumps embodying a stationary cylinder having therein an eccentrically mounted rotor provided with peripheral, mov- `able vanes, the vanes engage directly with the surrounding cylinder wall. Because the vanes must be movable upon the rotor, they can be held againstI the cylinder wall only through the action of gravity, centrifugal force, or springs. This definitely limits the pressures at which such pumps can operate to comparatively low. values, because the forces that hold the vanes against the cylinder wall cannot be made great enough to resist high pressures within the cylinder. By reason of the fact that the vanes are dragged over the cylinder wall while pressed against the same, wear takes place rapidly. Even if the vanes are made of softer metal than the cylinder, to permit the vanes to be rapidly brought to a good bearing against the cylinder wall and the greater part ofthe wear to take place in the vanes, there is inevitably a definite amount of grooving or scoring of the cylinder which makes it difficult to secure good bearings between the cylinder and vanes that are inserted -to take the place of worn vanes. Consequently, these pumps require a lot of attention in order to keep them in reasonably good working order, and even then, during the greater part of the life of a pump the bearings between the vanes' and theA cylinder wall are so imperfect as to permit. objectionable leakage of fluids past the vanes. Furthermore, if it be attempted to pump viscous materials, these will enter between the vanes and the surrounding cylinder wall and will cause leakage or slippage past the vanes, due to the fact that the holding forces for the vanes are not great enough to force the vanes through the viscous lmaterial intervening between them and the surrounding cylinder wall.

The ob/iect of the present invention'is' to improve the construction of pumps of the aforesaid type in a manner to overcome the aforesaid objections.

Or, viewed in one of its aspects, the present invention may be said to have for its object to produce a simple and novel rotary pump of the aforesaid type in which the seal between the rotor unit and the surrounding cylinder wall does not depend upon centrifugal force, gravity or springs, in which there is no scraping action of vanes or the like over a cylinder Wall, in which the working pressures may be high, in which the bearings are all of such a character that if the sealing against leakage or slippage past the vanes is initially eective, it will IQ- (Cl. S- 121) fluids between the engaged surfaces of the main and auxiliary cylinder. The rotor may consist of any usual or suitable cylindrical member mounted for rotation about a fixed axis within the cylinder. TheI vanes are hinged to the sleeve or auxiliary cylinder and are connected to the body of the rotor in such a manner that they may move down into slots in the latter or be drawn partly out of such slots to accommodate themselves to the variation in the radial width of the gap between the body of the rotor and the surrounding auxiliary cylinder in the different angular positions of the rotor. The connection between the body of the rotor and the vanes may consist of blocks or slides slidably fitted in the slots and having hinge connections with the vanes.

'Ihe various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawings, wherein:

Figure 1 is a' side view of a pump embodying the present invention; Fig. 2 is a top plan view of the pump; Fig. 3 is a central vertical section of the pump, namely a section on line 3-3 of Fig. 2; Fig. 4 is a section on line 4 4 of Fig. 3; Fig. 5 is a section-on line 5-5 of Fig. 3; Fig. 6

` is an end'view of the cylinder lining or auxiliary cylinder, detached from the pump; Fig.' '7 is a section on line 'l-lof Fig. 6; Fig. 8 is an end view of the cylindrical Vbody of the rotor, removed from the pumpyFig. 9 is a section on line 9-7-9 :of Fig. 8; Fig. 10 is a perspective -view of one of the vanes and Fig. 11 is a perspective view of one o of the Vblocks or slides to which the inner ends of the vanes are hinged.

Referring to the drawings,

ary bodyy of the pump. At one end of the l represents a cast- Aing which may be said to constitute the stationmember I is the pump cylinder 2 which is permanently closed at its inner end by an integral wall 3 and has at itsouter end a detachable closure or cover 4. The inner faces of the members 3 and 4 are parallel with each other. Accurately tted within the cylinder is a thick sleeve 5, the ends of which bear against the end walls of the cylinder. Consequently, while the member 5, or auxiliary cylinder, is rotatable within the stationary cylinder, there is an effective seal between the end andperipheral surfaces of the latter and the end and cylindrical walls of the main cylinder. Within the compound cylinder thus produced there is located a cylindrical rotor member 6 of smaller diameter than the interior of the auxiliary cylinder and eccentrically mounted so that at one side, which in the arrangement shown is the top, it fits against the inner surface of the auxiliary cylinder. In other words, there is between the members 5 and 6 the usual space I that is crescent shaped in a plane at right angles to the cylinder axis. 'Ihe rotor member 6 is fixed in any suitable manner to the end of a shaft 8 that extends out through the end wall 3 of the cylinder and through a suitable bearing 9 at some distance from said wall. The shaft 8 is parallel to the axis of the cylinder but is displaced therefrom a distance equal to the difference between the internal diameter of the auxiliary cylinder and the external diameter of the cylindrical rotor member.

The rotor member 6 and the auxiliary cylinder 5 are connected together by the vane elements of the pump which also constitute the driving connection between the rotor and the auxiliary cylinder. Since the rotor member 6 and the auxiliary cylinder revolve about parallel axes spaced apart from each other, they must'move more or less relatively to each other as they revolve, and therefore the connections between the same and the vanes must be such that the vanes will serve their intended purpose and yet leave the members 5 and 6 free to adjust themselves relatively to each other as they revolve. This can conveniently be brought labout by a vane construction which combines radial sliding movements with swinging movements. In the arrangement shown, the rotor member 6 has in the periphery comparatively wide, deep, radial slots II) extending through the length thereof. In these slots are fitted blocks II which may move into the slots untilthey lie entirely below the periphery of the member 6 or be moved outwardly so as to project somewhat beyond the member 6. Each of the blocks II has in the outer edge a groove extending throughout the length'thereof, which groove comprises an outer section I2 that is widest at the top and narrows gradually toward the lower end, together with an inner section I3 which is in the form of a cylindrical bore of a diameter larger than the width of the narrowest portion of the section I2. In other words, the groove, as viewed from one end of the block, has somewhat the appearance of a keyhole slot. In the auxiliary cylinder there are internal, longitudnal grooves I4 corresponding in angular spacing and in number to the slots .in the rotor member 6; these grooves being similar to the grooves in the blocks. The vanes are thick, flat metal plates I5 each having thickened marginal portions I6 along its long edges; such thickened portions being cylinders of the same diameter as the cylindrical portions of the grooves in the blocks II and the auxiliary cylinder 5.

It will be seen that the movable parts may all be inserted through the open end of the main cylinder after the outer cover has been taken oft. The order in which the different pieces are assembled is of no importance, but it is evident that if desired, the auxiliary cylinder and the rotor may rst be slipped into the stationary cylinder, the blocks may then be inserted endwise into the slots in the rotor member 6; and, after the members 5 and 6 have been placed in the proper angular positions relatively to each other, the vanes may be inserted endwise, each with a cylindrical edge portion tted in the cylindrical part of a groove in the auxiliary cylinder and the other cylindrical edge portion tted into the cylindrical section of the corresponding block in the rotor. Then, upon again attaching the cover ,or outer cylinder head, the assemblyis complete. Also, since the member 6, the blocks,

and the vanes are all of the same length, namely as long as the distance between the inner faces of the end walls and the stationary cylinder, seals are produced between the ends of all of these movable parts and the end walls of the cylinders. The principal wear takes place at Vthe ends of the rotatable parts, and the compensation for this may readily be made by initially making the lengths of the movable parts slightly greater than the distance between the cylinder heads as they appear in the drawings, gaskets being placed between the movable cover or head and the adjacent end of the stationary cylinder. Then, as wear takes place, thinner gaskets may be substituted until nally the detachable head rests directly against the end of the stationary cylinder. I

It will be seen that the vanes are positively connected to the auxiliary cylinder and only have a slight rocking movement relatively thereto. Consequently, all scraping action such as occurs when more or less radial vanes are dragged over the inner surface of a stationary cylinder is eliminated. Furthermore, because the wear in the hinge connections of the vanes with the auxiliary cylinder and the sliding blocks is slight, it is only necessary that the hinge joints be made with suiiicient accuracy to be effectively sealed initially, in order to insure that there will be no leakage or slippage past these joints after long and continued operation of the pump.

In the arrangement shown, there are four vanes spaced apart. In the stationary end wall of the cylinder are provided two ports I1 and` I8 disposed on opposite sides of the point or zone of contact between -the member 6 and the surrounding auxiliary cylinder. Either oi these two ports may constitute the inlet and the other the outlet because, with the parts constructed as shown, the rotor may be driven in either direction and the operation will be the same in either case.

The ports I1 and I8 open into the interior of the cylinder for a considerable angular distance beginning with the tips of the horns of the crescent shaped space between the rotor member 6 and the auxiliary cylinder. 'Ihe ports may be of uniform widths throughout their lengths, because where they are wider than the radial width of the crescent shaped space 1, the ends of the members 5 and 6 form closures therefor. Assuming that the shaft 8 is turning in the clockwise direction, as viewed in Fig. 4, air or other fluent material will be drawn vinto the cylinder 'through the port I8 by reason of the suction that is being produced by the righthand vane and the vane that points directly 75 down. By the time that the shaft has made somewhat less than a quarter turn, the righthand vane will have passed the lower end of between a pair of vanes.

y equalization of pressure results.

cylinder.

the port I8 and the lowermost vane will have just about reached the lower end of the port Il. Thus, there is a bodyof uent material trapped As the shaft continues to rotate, the section of the annular yspace within which this iluent material is conthe fluent material to Sine-ethe iiuent maned narrows, causing be placed under pressure.

`terial has nowhere else to` go, it flows out By the time that the through the port I1. shaft has completed almost half a revolution, the space within which the body of fluent material under consideration was originally confined will be reduced to the vanishing point, so that all of the uent material will have been forced out through the port I1. Of course, if there be back pressure in the port I1, there may be back flow through'this port until an' But,y no matter how great this back pressure is, it cannot drive the trapped fluent material back beyond the vane which is driving it ahead, because this vane is positively interlocked with the surrounding cylinder. Also, during the time of great pressure on the fluent material which yis "being forced out ofl the pump, the vane in advance of this confined or trapped body of fluent material prevents any leakage in the forward or clockwise direction between the rotor and the Consequently, the pump may operate effectively against high back pressure or, in other words, it may operate as a high pressure compressor. It, is also evident that if highly viscous materials are being pumped, they will be handled just as effectively as air or other materials, because there is nothing that they 'can do to disturb the proper functioning of the vanes as is the case where such materials can get between the vanes and the 'cylinder and hold the vanes out of engagement with the latter. Although it is common to have contact between cylindrical rotors and the surrounding cylinder wall, this has heretofore been a rubbing contact which soon results in suflicient wear to break the seal. In lmy construction, the relative movements between the members andi are radial rather'than circumferential, andtherefore there 4is no rubbing action that will affect the tightness of the seal between these two members in the zone where they happeri to be in engagement with each other. Here, again, a good initial seal lwill remain so.

Attention may be. called also to the fact that the openings or passages I9 leading from the periphery of the'r'otor 6 into the inner or lower end of each of the slots I0 serve as vents to permit accumulations of material that may occur in the slots to be forced out of the slots by the blocks as the latter travel inwardly in the slots.

'Y While I have illustrated and described with particularity only a single preferred form ofmy invention, I do not desire to be limitedl to' the exact structural details thus illustrated anddescribed; but intend to cover -all forms and arrangements'whlch come within-the definitions ofv my invention constituting the appended claims.

I also wishA to have it understood that Iwhereas I have illustrated my invention as applied to a pump and described'itin detail as such, the same principles are applicable to machines in which ports, the rotor having peripheral radial slots,

slides in said slots, and vanes each hinged at its inner -end to one of said slides and at its outer end to the auxiliary cylinder.

2. In a rotary pump of the type comprising a stationary cylinder having inlet and outlet ports, and a rotor mounted eccentrically in the cylinder and having thereon movable peripheral vanes: an auxiliary cylinder in the form of a sleeve fitting and rotatable in the said stationary cylinder and contacting with the periphery of the rotor at a point between said ports, radially movable elements on the rotor, and hinge connections between the outer ends of the vanes and the auxiliary `cylinder and between the vanes and said radially movable elements.

3. In a rotary pump of the type containing aA 'groove in the corresponding block and one edge into one of the grooves in the auxiliary cylinder.

4. In a rotary type pump, a stationary cylinder having end walls one or vwhich is detachable, 'a cylindrical, sleeve tting and lrotatable within said cylinder, a cylindrical rotor member smaller in diameter than the internal diameter of" the sleeve positioned eccentrically within the latter,

said rotor member having peripheral slots ex-A tending lengthwise thereof, blocks arranged and radially slidable in said slots, each block having a longitudinal grooveterminating at the bottom in an enlarged cylindrical bore, said sleeve havthe blocks, vanes having thickened cylindrical edge portions, one of said edge portions of each vane fitting in the cylindrical bore of one of the blocks and the other in the cylindrical bore portion of one of the grooves in said sleeve; the sleeve, rotor member,- blocks and vanes `being all ofA the same length as the. cylinder whereby they are caused to bear against the end walls of the cylinder and any one or all of them may be slid out of the cylinder upon removing the detachable wall. l

Y BENJAMIN B. STERN.

-ing in the inner face grooves similar to those in

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