US2164888A - Variable delivery pump - Google Patents

Description

y B. SASSEN ET AL VARIABLE DELIVERY PUMP Filed Feb. 24, 1936 s Sheets-Sheet 1 INVENTOR. lfz'q P FEW/W20 Jkryf/y BY /%/Y5 fP/xrr 3,, 4 ATTORNEY.

July 4,1939. SASSEN ET AL 2,164,888

- VARIABLE DELIVERY PUMP Filed Feb. 24. 1936 3 Sheets-Sheet 2 ATTORNEY.

July 4, B sAssEN ET AL VARIABLE DELIVERY PUMP Filed Feb. 24, 1936 3 Sheets-Sheet 3 .Z IIIII V gnnnmuuu1i-I5m v 79- 1 do 92 it I 52 J4\ fkf rP/CK 11/44.)"

ATTORNEY.

Patented J y 4, 3

UNITED STATES VARIABLE DELIVERY PUMP Bernard Sassen, Hans Ernst, and Frederick S.

Haas, Cincinnati, Ohio, assignors to Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation of Ohio Application February 24, 1936, Serial 3 Claim.

This invention relates to pumping mechanisms, and more particularly to an improved reversible variable delivery pump. 4

One of the objects of this invention is to provide a variable delivery pump which is composed of a relatively small number of parts and therefore relatively inexpensive to manufacture.

Another object of this invention is to provide a variable delivery pump which is so constructed in that two or more of them may be connected in tandem for simultaneous operation which is now impossible with present commercial types of A further object of this invention is to provide 1-- a simple compact variable delivery pump mechanism which has a high degree of efliciency; which is self-lubricating and which has a satisfactory range of adjustment.

Other objects and'advantages of the present 2 invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Referring to the drawings in which like reference numerals indicate like or similar parts:

Figure 1 is an elevational view of a pump embodying the principles of this invention.

Figure 2 is a section on the line 2--2 of Figure 1.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a vertical section on the line 4 of Figure 2.

Figure 5 is an elevational view partly in section and as viewed from the opposite side of Figure 1.

Figure 6 is a detailed view of the pump adjusting member.

Figure '7 is a cross section showing a modified form of distributor head.

Figure 8 is a section on the line 8-8 of Figure 7.

Figure 9 is a section on the line 9-9 of Figure 7. Y

Figure 10 is a detailed section on the line Ill-l 0 of Figure '7. I

Referring to the drawings, the reference numeral l0 indicates the casing of the pump and this casing hasa pair of legs I l and I2 depending therefrom by which the same may be supported and fastened upon a suitable support.

A hollow shaft I3 is supported on a pair of spaced anti-friction bearings l4 and i5 carried by the end walls of a substantially cylindricallyshaped chamber, and these bearings also, serve to hold the shaft l3 against axial movement. The shaft I3 has a cylindrical portion [6 projecting beyond the bearing I4 for receiving and supporting a distributor head I1. A pipe 18 is threaded into the distributor and this pipe passes through an opening l8 in the pump casing Ill, as more particularly shown in Figures 2 and 3, and serves to hold the distributor against rotation by the shaft. In other words, the distributor head is stationary and the shaft rotates. A pipe 19 is also threaded into the distributor diametrically opposite the pipe l8, and this passes through an opening 20 formed in the casing ill but suitable packing 2i surrounds the pipe 19 so as to form an oil seal and prevent any leakage of oil.

As shown in Figure 3, the distributor H has a pair of internal arcuate grooves 22 and 23 formed therein adjacent the ends of the intake and delivery pipes. These grooves have an arcuate extent of about degrees. lhey serve as intake and delivery chambers and are capable of receiving and delivering fluid to a plurality of pump pistons at the same time.

The shaft i3 has a circumferentially enlarged portion 26 located between the bearings l4 and I5, and in this portion and equally spaced about its periphery there are drilled a plurality of holes 25. These holes are preferably uneven in number and in the present instance there are seven of them, although any other uneven number could be utilized.

A ring 36 has seven radially extending drilled and lapped holes 21 formed therein. The ring 26 is secured to the shaft by being shrunk on to the portion 24 and in such relation that the axes of the holes Zl are co-incident with the axes of the holes 25 formed in the portion 24. The holes 25 are slightly larger in diameter than the holes 2], whereby the holes 21 may be lapped after assembly, if so desired.

Piston members 28 are mounted in the holesor cylinders 27. Each of the large holes 25 has a small co-axial hole drilled in the bottom thereof which intersects a longitudinally extending drilled hole 30 which communicates with a port it. Eihe individual ports 36 are adapted successively to register with the chambers 22 and 23 upon rotation of the shaft. It will thus be seen trically adjusting the ring 3|.

that some of the cylinders containing pistons 28 will be connected to the intake pipe i9 and that others will be connected to the delivery pipe i8. A ring 3| surrounds the outer ends of the pistons 23 and a rocker shoe bearing 32 is interposed between the end of each piston and the inner surface of the ring. The ring 26 which carries .the pistons 28 has flanges 33 and 34 formed onopposite sides thereof forming a carrier and as shown in Figure 5 the flanges have a plurality of radial slots 35 formed therein which receive pintles 38 which extend laterally from the rocker shoe bearings.

The rocker shoe bearings are thus pivotally supported by these pintles and the slots 35 are 0! sufllcient length that the bearings may move in and out with the pistons. The bearings are mounted in the supporting ring in accordance with the direction in which the shaft is to be rotated and, as viewed in Figure 5, if the direction of rotation is counterclockwise as indicated by the arrow 31, the bearings are mounted so that the pintles 36 are behind the leading edge 38 of the rocker shoe bearings because during rotation this leading edge is spaced to rise a little from the surface with which it is in contact in order to provide the necessary film of lubrication.

The ring 3| is supported on,a pintle 39 whereby the center of the ring may be moved eccentrically with respect to the center of the shaft to form a crescentlc' chamber and cause the necessary pumping action when the shaft is rotated. The following mechanism is provided for eccen- A cup-shaped sleeve 40 is slideably mounted in a bore 4| formed in the pump casing l0 and displaced 90 degrees with respect to the pintle 39 'and a spring 42 is interposed between this sleeve and a plug 43 threaded in the end of the opening 4|. The spring acts in a direction to swing the ring 3| in a clockwise direction about its pintle 39. Diametrically opposite spring 42 is an adjustable stop 44 which is slideably mounted in a bore 45 formed in the pump casing. A key 48 is provided for holding the stop against rotation in its bore while still preventing axial movement thereof. An adjusting screw 41 is threaded in the end of the stop and has a shoulder 48 formed thereon which abuts against a fixed member 49.

The screw has a reduced shank 50 which prohats to the exterior 'of the housing and is provided with an operating knob 5|. Figure 6, this knob has an integral pointer 52 which moves relative to graduations 53 formed on the fixed member 49. These graduations may consist of a zero mark 54 which indicates that the center of the ring is concentric with the center of the shaft and therefore since there is no eccentricity the pistons 28 will neither move in nor out when the shaft is rotated. Upon ad- Justment of the knob 51 in either direction from the zero position the ring will be moved eccentrically with respect to the center of the shaft and a pumping action will take place and the directions of fluid flow through the pump will depend-upon which Side of the center of the shaft the ring has been displaced.

In operation, the pistons 29 are continuously As shown in Figure 3 that as each piston approaches the end I of its discharge stroke that the corresponding port 3| is disconnected from the chamber 22 by the portion 56 intermediate the arcuate grooves or chambers. It will also be noted from this figure that as the pistons reach the end of their intake strokes that the portion 51 closes the respective ports 3| a sufficient length of time to permit the piston to initiate its pressure stroke and thereby place the fluid under some pressure before its discharge into chamber 22.

A branch line 58 is connected as shown in Fig- ,ure 2 between the intake line and the bottom of the pump casing to supply lubricating fluid to the interior of the casing to maintain all of the moving parts lubricated. A cover plate 59 may be secured to one end of the pump casing to prevent the escape of the oil when the pump is used alone and by this means the lower portion of the casing will have a certain amount of oil therein which, by rotation of the shaft, will be carried to the moving parts. As shown in Figures 2 and-4 the ring 3| has a kerf 60 out therein which permits the oil to reach the rocker shoe bearings and supply lubrication thereto.

In order to prevent undue pressures building up, a relief valve 6| may be interposed in the distributor head between the outlet and the inlet to permit high pressures to be relieved into the intake side, thereby short circuiting the pump.

the end of the shaft and the driving member of a prime mover. Similarly, the plate 59 may be provided with an opening through which an adaptor 84 may be inserted having a key for engaging the key slot 66 formed in the bore of the shaft. This adapter may have a cross rib 81 on the end for engaging an Oldham coupling which may be inserted between two pumps if they are to be connected in tandem. From this it will be seen that the shaft may be driven from either end by a prime mover and that'a second pump may be aligned and coupled with the first pump in tandem for actuation by a common prime mover.

In order to prevent the lubricating oil from building up under too'much pressure in the pump casing a return pipe 88 may be connected by an elbow 89 to the opening 10 formed in the top of the pump casing, and since this connection is at the top of the casing the entire chamber filled with oil, thereby insuring that all of the parts are thereby adequately lubricated.

In Figures 7, 8, 9 and 10 of the drawings there is shown a-modified form of the invention, and

more particularly a modified form of distributor head. In these figures, the distributor head, indicated by the reference numeral ll, comprises an annular ring, as shown in Figure 9, which is held against rotation'by a set screw 12 and is provided with a plurality of piston rings 13 to pre- -vent leakage axially of the periphery of the memsince the same is slightly smaller in outside diameter than the diameter of the bore, so that it is free to adjust itself slightly in accordance with the position of shaft l3, upon which it is supported.

As shown in Figure 9, the member II has diametrically opposed arcuate grooves 14 and I5 formed on the inside thereof, which serve as intake and delivery grooves, the intake groove'being connected by bores 16 to arcuate groove 11, as shown in Figure 7, and this groove, as shown in Figure 7, connects to the intake port 18. The delivery groove 14 issimiIarIy connected as by channels 19 to an arcuate groove 88 which communicates with the delivery port 8|. By means of this construction a better seal can be maintained between the fixed ports and the running ports.

In addition, means have been provided for establishing hydraulic balance between the distributor head II andthe end of shaft l3 which it surrounds. Since the distributor head is slightly smaller in diameter than the bore 82 in which it is contained, fluid from side port 80 may flow around the outside of the distributor head between the rings 13 which are on opposite sides of the port 88. A radial hole 83 serves to conduct the fluid from the annular space 84 into an arcuate groove 85 formed on the inside of member II, and this groove has an angular extent equal to the total angular extent of port 14 and a width equal to one-half of the, width of port 14. The pressure fluid in this groove is permitted to continue its flow through a second radial bore 86, longitudinal bore 81 and a third radial bore, not shown, into a second arcuate groove 85' which is indicated in Figure '7. The arcuate groove 85' is of the same size as groove 85 and it will be noted from Figure '7 that the grooves 85 and 85' are spaced equal distances longitudinally from the port 14 and are located diametrically opposite thereto, and since each of the grooves is onehalf of the width of the port 14 but of equal angular extent, it will be apparent that the pressure in these two grooves will cooperate to balance the opposing pressure in port 14.

Similarly, the incoming pressure at port 11 is permitted to flow around the distributor head II in the annular space 88 between the rings 1310- I cated at opposite sides of the port 11. As shown in Figure 10, a radial bore 88 connects the annular space 88 with an arcuate groove 88 formed on the inner side of the member II. This groove is connected by radial bore 9| and longitudinal bore 82 to a second arcuate groove 83, as more particularly shown in Figure 8. The arcuate grooves 98 and 93 are one-half the width of port 15 and are of equal angular extent therewith but diametrically opposed thereto, as shown in Figure 7, whereby they serve to balance the pressure at port 15 in the same manner that the grooves 85 and 85' balance the pressure at port 14. Improved means have thus been provided forv hydrostatically balancing the end of shaft [3 relative to the distributor head.

There has thus been provided an improved variable delivery pump comprising a minimum number of parts having means for automatically lubricating the same, thereby reducing friction so that the pump has a high degree of efilciency; and one which is so constructed that it may be connected in tandem with anotherpump of the same or different type.

We claim:

1. In a variable delivery pump, the combination of a housing having a cylindrically-shaped chamber formed therein, a shaft passing through the axial center of said chamber, an integral annular portion formed on said shaft and rotatable in said chamber, radial piston and cylinder combinations carried by said portion, a displacement control ring surrounding the ends of said pistons, rocker shoe bearings pivotally mounted in the periphery of said portion between the ends of said pistons and the inner surface of said ring, means supporting said ring for adjustment eccentric to the axis of said shaft to vary the stroke of said pistons, a distributor head supported by said shaft exteriorly of said chamber having an intake and delivery pipe connected thereto, means carried by said shaft forming fluid connections between said cylinders and said distributor head and means hydrostatically balancing the head whereby displacement of the shaft due to pressure differentials created in the head by the pump is prevented.

2. An hydraulic mechanism of the character described, including a supporting-casing, a rotor journaled in the casing including multiple radial cylinders and pistons movable therein, a carrier member movable with the rotor, an adjustable ring pivoted to the casing in circumscribing relation to the rotor and associate parts, means for variably displacing the ring with respect to the rotor to vary the action of the pistons in the cylinders, and floating rocker shoe bearings corresponding in number to the pistons loosely carried by the carrier for rotation therewith and interposed between the respective pistons and the inner face of the ring for sliding movement with respect to the ring, said shoes being laterally oifset with respect to the axes of the respective pistons in the direction of rotation of the rotor, means for supplying lubricant toflood the space between the rotor and ring whereby on rotation of the parts the leading edges of the rocker shoes will be deflected proportionate to the load to counteract the piston pressure and maintain a proper oil film between the shoes and ring under said varying load conditions, said rotor having a laterally projecting portion, a floating distributor head mounted on said laterally projecting portion, the rotor having grooves affording communication between the respective cylinders and the distributor head, the casing having a portion circumscribing the head in spaced relation thereto, yieldable means for maintaining an oil seal between the casing and floating head, and means for effecting an hydrostatic balance of the floating distributor head whereby deflection of the rotor by any unbalanced pressure conditions normally created between rotor distributor headand casing during operation of the device is counteracted.

3. A pump structure of the character described, including a rotor having an enlarged head providing pump cylinders, anti-friction bearings disposed at opposite sides of said head, a casing enclosing the head and engaging the bearings whereby said head is supported for free rotary movement within the casing, said rotor having a ported axially extended portion," the casing having a corresponding extension circumscribing the extending portion of the rotor, a distributor head mounted on said rotor extension in close fitting engagement therewith, the casing extension having a recess circumscribing the head, means securing the head against rotation relative to but for radial movement in all directions as respects the circumscribing portion of the casing, said casing having intake and discharge ports formed therein in axially displaced relation with respect one to the other, the distributor head having passages aligned with said ports, yieldable means providing a seal against axial interpassage fluid flow in the space between said distributor head and casing, and means hydrostaticaliy balancing the distributor head as respects the diiterent pressures existing at the intake and dlicharge passages therein, whereby distortion of t e rotor extension due to said pressures is prevented and the head is free to move in the casing in response to axial variations in position 01' the rotor extension.

BERNARD SASSEN. HANS ERNST. FREDERICK S. HAAS.

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