US1876370A - Feeding device - Google Patents

Description

Sept. 6, WEBER FEEDING DEVICE Filed March 26, 1930 2 Sheets-Sheet l m22/ fiala 7*"-4/ Sept. 6, 1932. H, WEBER 1,876,370

FEEDING DEVICE Filed March 26. 1930 ZvSheets-Sheet 2 Patented Sept. 6, 1932 PATENT GFFICE HERMANN WEBER, 0F SPIEZ, SWITZERLAND FEEDING' DEVICE Application led March 26, 1930, Serial No. 439,257, and in Germany .Tune 181, 1929.

This invention relates to a device for feeding liquid or gaseous fluids by means of an eccentrically supported piston and a radlally directed blade or a plurality of such blades, extending from said piston into the casing thereof. Feeding devices of this type suffer firstly, from the difliculty of keeping lsaid rotary piston in its casing or cylinder tight, in that leakages arise in the case of a deformation of the casing or cylinder, and secondly, from the difliculty of preventing the blade from jamming in its chamber 1n such case. It is to be borne in mind that blades arranged in the above-stated manner not only reciprocate, but also oscillate when theecceng trically supported piston is in motion, and that, owing to the very great number of revolutions of feeding devices of the type in question, viz. up to 2000 revolutions per minute, the generation of frictional heat is very great which is another and somewhat frequent cause for jamming. If a feeding device of this type is used in connection with, or for, a compressor, the heat of compression constitutes an additional cause for jamming. From these and other reasons feeding devices with an eccentrically supported piston have even up to the present time not been generally approved in spite of the advantages presented by the rotary motion of the driving member or members.

The difficulties stated in the preceding paragraph are encountered especially if the pivot of the blade in the casing is stationary and the blade is shiftable in this stationary pivot. In such case a considerable accumulation of heat in that pivot takes place, and this entails the necessity of either making the pivot bearing particularly large or of providing cooling means for it. The heat accumulation is smaller if the pivot is located in the blade itself and this latter is arranged in a slide guided in the casing, in that in this case the heat is abstracted throughout the entire length of the slide guide.

Hitherto the pivot of the blade has always been undivided, which necessitates a comparatively long guide path for the bearing in the casing whereby tightening or packing the piston with respect to the cylinder consequences are that the tightening or packing of the piston at the cylinder wall and the efficiency of the device are unfavorably influenced. Besides, the lubrication of the pivot is rendered more diflicult, as the lubricant easily becomes hardened by the heat.

Furthermore, the closed bearing is subject to a comparatively great expansion by reason of its large bulk which is also a cause for jamming if it is accurately fitted into its uide path.

All these difficulties are completely done away with by my present improved feeding device, the main characteristic feature of which resides in that the bearing for the pivot of the blade located at the piston is 7 formed by two lateral members which I-have termed lshoes and which are not connected with one another in any way. This invention is illustrated diagrammatically and by way of example in the accompanying drawings in which Figure l is a vertical section through a feeding device designed according to this invention, the section plane standing at right angles with respect to the cylinder axis; Figure 2 is another vertical section, the plane of 3 which stands at right angles to that of Fig. l; Figure 3 is a modification, drawn to a much larger scale, of the sliding bearing for the blade, located in the blade guiding chamber (compare therewith the middle portion of the lower half of Fig. l) and Figure 4 is a separate view of one of the shoes (20) of Fig. 3, seen from the inner face thereof.

rIhe cylinder of the device consists of a chiefly hollow member l which is open at both sides and is there closed by covers 2 and 3 connected with the member l and with one another by bolts 4. The main part of the hollow space in the member 1 is cylindrical, that is to say, constitutes the cylinder, and a shaft 5 extends coaxially with this cylindrical space through itand through the covers, to one end of which shaft is attached a small pulley 6. To the shaft 5 is aflixed, within said cylinder, an eccentric member 7 support- 'rotation of the member 7 9 is a blade which is attached to the piston in the manner shown in Fig. 1 and takes part in the reciprocating, as well as in the oscillating motion of the piston 8. Vhile the piston 8 is oscillating, as well as reciprocating vertically, so as to move the blade 9 up and down in the chamber 10 provided for it in the mem-I ber 1, all successive portions of its peripheral surface contact successively with all succesive portions of the inner peripheral wall of the cylindrical space in the member 1, in consequence whereof the sickle-shaped working spaces or chambers 11 and 12 are continually and alternately increased and decreased. 11 is the suction chamber, 12 the pressure or delivery chamber. The chamber 11 receives the respective fluid through the suction valve 15, the intermediate space 14 and the passage 13, and from the chamber 12 the fiuid escapes through the passage 16 and past the delivery valve 18 into the space 17 from which it is further conveyed away.

Now, the pivot portion 19 of the blade 9 is tightly fitted between two shoes 20 having each a concave side contacting with said pivot portion, and a fiat side contacting with one of the flat walls of the chamber 10 in which the blade, or its pivot portion with the shoes respectively, moves up and down, the blade at the same time also moving to and fro in the plane of the piston 8, and its pivot portion turning to and fro between the shoes.

The blade 9 is provided with lubricating channels 23 and 24 Figs. 1 and 3), as well as with a lubricating passage 21 shown in dotted lines in Fig. 3. This latter passage communi- Cates with the chamber 10 into which the lubricant is introduced through a bore 25 (Figs. 2 and 3) The lubricant is sucked into this Chamber and further into said passages so as to lubricate the blade everywhere, including the shoes, and the sucking action is effected by the vertical reciprocations of the piston 8 with the blade 9.

The length or height of the guide faces in the chamber 10 for the shoes need only be very moderate so that the casing 1 need not be extraordinarly high, and owing thereto the great feeding or conveying pressure produced by the respective fluid while the feeding or conveying is going on cannot deform the casing 1 in that this lat-ter is fully able to stand them.

In order to reduce the friction arising between the shoes and the walls of the chamber 10 ball-bearings or roller bearings 22 (Figs. 3 and 4) can be provided, the balls or rollers contacting, of course, with the respective Walls. rl`he circumference of the balls or rollers is preferably a little more than the length of the stroke of the blade 9 so that non-uniform wear and tear of the rollers or balls is prevented.

I claim:

1. A feeding device for liquid or gaseous fiuids, comprising, in combination, a casing having a cylindrical space; an annular piston arranged eccentrically in said space; an eccentric located in said piston; means for rotating said eccentric; a blade -extending from said piston into a chamber provided for it in said casing, the blade-portion most remote from the piston being designed as a pivot for it; and two independent shoes enclosing this pivot-portion of the blade between them and guiding it between the walls of said chamber, said blade portion having a passage therein for lubricant, said passage running lengthwise of the blade, and a plurality of other lubricant passages communieating therewith and terminating adjacent the shoes, to feed lubricant to said shoes and thus also assist in maintaining fiuid-tight joints substantially as and for the purposes set forth.

2. A feeding device for liquid or gaseous fluids, comprising, in combination, a casing having a cylindrical space; an annular piston arranged eccentrically in said space; an eccentric located in said piston; meansffor rotating said eccentric; a blade extending from said piston into a chamber provided for-it in said casing, the blade-portion most remote from the piston being designed as a pivot for it two independent shoes enclosing this pivot-portion of the blade between them and guiding it between the walls ofv said chamber; and rotary antifrietion members inserted into said shoes on'the side where they contact with the chamber walls, and substantially enclosed by said shoes, said' blade portion having a passage therein for lubricant, said passage running lengthwise of the blade, and a plurality of otherlubricant passages communicating therewith and terminating adjacent the shoes, to feed lubricant to said shoes and thus also assist in maintaining fluid-tight joints substantially as and for the purposes set forth. u,

3. A feeding device for liquid or gaseous fluids, comprising, in combination, a casing having a cylindrical space; an annular piston arranged eccentrically in said space; an eccentric located in said piston; lmeans for rotating said eccentric; a blade extending from said piston into a chamber provided for it in said casing, the blade-portion most remote from the piston being designed as a pivot for it; two independent shoes each bounded by a substantially hemi-cylindrical surface on one side and by a plane surface on the other; the chamber into which said blade projects being likewise provided with plane surfaces engaging the plane surfaces of the shoes, the said cylindrically curved surfaces bein in contact with portions on the blade whic are 'ven the same curvature so as to make a tig t joint therewith, said blade portion having a passage therein for lubricant, said passage running lengthwise of the blade, and a plurality of other lubricant passages communicating therewith and terminating adjacent the shoes, to feed lubricant to said shoes and thus also assist in maintaining fluid-tight joints, substantially as and for the purposes set forth.

In testimony whereof I alix my signature.

` HERMANN WEBER.

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