US2103474A - Reversible planetary piston pump - Google Patents

Description

REVERSIBLE PLANETARY PISTON PUMP Filed Dec. 19', 1,936

"l /6 il 2 Sheets- Shea 1N VEMTOIQ ',US'CLV Rudolf Lind berg *1I* 28, i937. G, R LLNDBERG 193,474

REVERSIBLE PLANETARY PSTON PUMP Filed Dec, 19, 195e 2 lshets-sheet 2 Z /0 r,72 \,C

@151m Rudolf Lindberg \NVENTOR Patented Dec. 2s, 1937 gleam PATENT OFFICE REVERSIBLE 4PLANETAIY PISTON PUMP l Gustav Rudolf Lindberg, Overum, Sweden Application December 19, 1936, serial No. 116,669

, In Denmark February 11, 1936 '1 claims. (01. 10a-431) The present invention relates to an arrangement in a reversible planetary Piston pump of the kind, whose pump casing has two Ypump* cylin-V ders, which are connected with each other and ings are provided, and inwhich pump the'impeller consists of two pump pistons, each provided in its cylinder, and an intermediate member radiallyY connecting theA said cylinders, the

lV said impeller being adapted to bc actuated byV driving and guiding means' soV constructed that an eccentric motion can be imparted to'eithe piston, so that they are caused to move synchro` nously with each other. Y

15 One object of the invention is, in a driving means, in which only one of the pistons is actuated to accentric motion'on a shaft in its cylinder, to so shape the guiding means that an exactly corresponding eccentric motion is imparted to theother piston. Preferably the guiding means consists of a roller or cylindrical shaft extending through slots'in the connecting portion and rotatably mounted in the casing.

A further object of the invention is to provide 25 means of such a kind that an absolutely effective Y tightening is eifected bothV between pistons and the walls of the workingcylinders and between the said cylinders and the suction'and delivery side after each strokeof the pistons, and thatin 51 the last mentioned positions cushioning means arise in connection with the sealing means so as to obtain a smooth and quiet run of the impellersrduring the strokes., 'V VThe pumping device may just as advanta- 3,3: geously be use dY as a machine, a water motor or Y The Vaccompanying drawings illustate, way

of example, a constructional form ofV the'invention.

,0- Figure; 1 shows a section perpem'iicularlyv toV with only half the pump and showing a detail 5o Von a modifiedV scale.

`Figure 6 shows a modied detail.

The pump casing comprises two cylinders I, 2V

located side by side, somewhatspaced with respect to one another and connected with'each r 55 other by means of an intermediate portion, in

between which the suction and delivery ope11.

which suction and delivery openings 3, 4 are provided right opposite to each other about perpendicularly to the driving shaft. If desired, the ducts `opening into the suction and delivery openings may be arranged parallel with the driving 5 shaft, as indicated in dashed'circular lines, atzl and 8, in Figure 1. In a constructional form of the said kind the outer ends ofthe openings 3, 4 are shut off, so that a suction and pressure cham-V ber, respectively, is formed in the pump casing proper. The pump casing is provided with one stationary and one removable cover 5 and 6, respectively. 1 Y Y The impeller consists of'two pistons Sand HL, one in each cylinder and an intermediate meml5 ber II, rigidly connecting said pistons. The said member, with concave side faces merges with the cylindrical faces o-f the pistons. The pistons 9, Ill are coated with a coating I2 of yielding or elastic material, for example, a soft metal alloy, caoutchouc or the like, so as to facilitateV smooth sliding of the. pistons on the cylinder walls and to provide for an elective sealing elect Vagainst the walls, also in axial direction. Moreover, the pump pistons and the cylinder walls by this arrangement need not be made with the precision required in case metallic surfaces are to cooperatewith each other. Preferably, also the intermediate memberV II is provided with such a coating I2', integral with the coating I2, so that 30 the coating may be applied to the impeller Without joints. These coatings, however, may ,b e dispensed with, without the purpose of the invention beingabandoned, or they may b e varied in such a `manner that a coating I2" is applied to the 35 cylinder walls, instead of being applied to the* pistons, as shown in Figure 5.

`Adriving shaft I3,extendsconcentrically into the pumpV cylinder I and on the same there is provided a cam I4 to Vdrive the piston 9 around.' 40 Said cam is so shaped that at the driving the center of the piston moves along acircular path I5 and itsperiphery rolls on the cylinder wall. In Vthe member II there is provided a slot I9 and in thecovers 5, 6 slots I8. A cylindrical shaft or 45 roller I'I extends through the slot I9 and is loosely or rollably mounted in the slots I8. The slots have av largerextension in the plane 'through the piston axes and the longitudinal direction of the casing covers', respectively, than the shaft il'. 50 Thus, the extension of the slots I8 is'about equal to the sum of the shaft diameter and theradius Vof-the Vcircle about which the shaft center of the pistonsoscillates, the central line ofthe said slotsV I8 coinciding with the transversal plane through 55 the center of the pump casing. Thus, during the pumping work, in addition to a rolling motion, also an up-and-down motion in the slots I8 may be imparted to the shaft I'I, the connecting member II being swingable and displaceable relatively to the shaft.

The shaft I'I has an annular groove 20, so that liquid, which may enter the slot I9 is able to circulate in the same without resistance, and moreover the ends of the shaft may have convex shape, as shown in Figure 2, in order to admit of such circulation also in the slots I8. The slot may be replaced by holes or ducts. The walls of the slot I9 and, if desired, also those of the slots I8 are provided with a coating and a guiding surface, made of some material resistant to wear and tear, as indicated at 3D.

At the limiting edges of the suction and delivery openings there are provided groove-shaped axial recesses 22 in the cylinder walls. On the impeller about at the place where the concave surfaces of the connecting member I I merge with the cylindrical surfaces of the pistons 9, I0 there are provided rounded axial sealing edges 23 of a shape corresponding approximately to the shape of the recesses 22 and, for the purpose of sealing oif the respective cylinder chamber, cooperating with the same in certain positions of the impeller.

In the piston 9 spring-acting roller or antifriction bearings may be provided between the cam VI4 and the bearing surface of the piston, marked by a dash-and-dot line 32 (Figure 6), in order to obtain a yielding motion between the elements. Or also, a play may be provided between the shaft I3 and the cam, indicated at 33, by which also a certain spring-action can be obtained between said elements. 34 indicates a preferably square key, which may be used in this case for connecting the members I3 and I4 with each other and located substantially opposite said play.

The operation is as follows. In the position shown in Figure l the upper pump piston 9 has accomplished one stroke. The sealing edges 23 extend into the recesses 22 and block the cylinder chamber a from the suction and delivery openings, so that the liquid sucked into the chamber during an earlier stage of the stroke is kept enclosed there. The lower pump piston I0 with its outer end rests against the cylinder wall and, in a fluid-tight manner, blocks the two chambers b and c, from each other, i. e. the delivery side from the suction side. During this movement liquid present in the chamber b is expelled in the direction of the arrow in Figure 1 and sucking-in is effected in the chamber c, as is also clear from the drawn arrows. When the shaft I3 continues to move in the direction of the arrow the piston 9 is swung to the left, the piston I0 to the right, and the periphery of the piston 9 is caused to contact with the cylinder wall, the sealing engagement, at 22, being released. The liquid in the chamber a is pressed out through the opening 4, the volume of the chamber being successively reduced according as the rolling motion of the piston 9 on the cylinder wall continues. When the shaft has turned half a turn the piston 9 has the same position as the piston Ill of Figure l. The liquid in the right part of the chamber a is still being pressed out, vacuum arising in the left part, so that sucking of liquid takes place. The more the piston 9 continues to the position shown in the figure the more the volume of the chamber a is increased and the more liquid is sucked until the shaft has rotated a whole turn, when the chamber is again completely blocked.

On account of the shapes of the guiding shaft I1 and of the slots the piston I0 will, of course, move in the indicated direction of the arrow, i. e. synchronously with and in a direction opposite to that of the piston 9 with its center of axis along the circle I6. Thus, if the piston I0 is moved in the direction of the arrow its surface rolls against the cylinder wall under permanent sealing between the suction and delivery side, during which the volume of the chamber c increases more and more at the cost of the chamber b. When the driving shaft has rotated half a turn from the shown position the piston Ill has reached a position which corresponds to that of the piston 9 in the drawings and seals the common chamber b, c from the suction and delivery openings.

As is seen from arrows marking the directions of flow the medium passes spirally through the pump.

When the piston I0 is moved towards and away from the position shown in Figure 1, the angular speed of the piston I0 is increased on account of the displacement of the shaft Il' upwards in the slots I8, so that the volume of the chamber b decreases more rapidly than the volume of the chamber a., by which the total outflow can be kept practically continuous. The reverse course of motion will take place when the piston IU with its center moves within the upper half of the circle I6.

The depth of the recesses 22 is preferably made somewhat larger than the height of the sealing edges 23, so that chambers or cavities 3l are obtained (Figure 4). During the pumping movements the liquid remaining in the said cavities will act as liquid cushioning means, so that when the sealing edges 23 enter the recesses 22 a noiseless and quiet working without shocks and blows is obtained also in case of considerable suction heads.

The two cooperating portions 2l and 23 may be arranged in a contrary manner, as shown in Figure 5, recesses 22' thus being provided on the pistons and sealing edges 23 on the cylinder walls.

On account of the shown concave shape of the connecting member a smooth transition is obtained between the suction and delivery openings and the pump chambers. Therefore, the pumped out liquid moves through the pump in an even flow and on account of the double-acting construction Ysubstantially in a continuous flow without eddies being formed, which is of a special importance when pumping, for example, a liquid such as milk or the like, which, in case of eddes, easily may be subjected to separation. The efciency is kept high thereby that the pump need never work with unreliable sealing between the suction and delivery sides.

The removable cover 6 is carried by bolts 25, which extend through the casing (see Fig. 1) and are provided with heads indicated by 24. The operating member 26 is provided with a screw 21, which extends through the hub 28 of the stirrup member 29. The point of the screw is guided in a recess in the cover 6. The ends of the arms of the stirrup member 29 are arranged as fastening members (claws or the like) which engage the body 25 of the respective bolts. When the cover 6 is to be removed from the position shown in Figure 3 the operating member is turned in such a manner that there is no pressure on the stirrup member, after which the latter is turned in anti-clockwise direction, until it has been completely liberated andV the 'cover can be removed so that the interior parts of the pump will be easily accessible for inspection, cleaning and repairing, if any.

Having now described my invention, `what I claim as new and desire to secure by Letters Patent ist. Y

l. In a reversible planetary piston pump, a Vcasing comprising two cylinders arranged side by side and having openings in their adjacent sides communicating with one another; inlet and outlet openings communicating with said cylinder openings at opposite sides, an impeller in said casing, said impeller comprising two rotary pistons, arranged one in each cylinder, and a rigid connecting member between said pistons Yconstituting a partition between the inletV and outlet openings, a single eccentric drive operatively en gaging the piston of one of the cylindersand imparting a rotary oscillation to said piston, and guidingrmean's -for said connecting member for causing the piston in the other cylinder to move synchronouslyjwith the piston in the rst cylinder, said guiding means consisting of a shaft eX- tending through a slot of the connecting member and being movably mounted in slots of the Walls of the pump casing, the slot of the connecting member and the slots inthe walls of the pump casing having a larger extension inthe plane through the piston axes then said movable shaft, the latter receiving simultaneously a rolling motion relatively to its own axis and a longitudinal movement relatively to the slots in the Walls of the pump casing.

2. A reversible planetary pistOn pump as claimed in claim l, in which the connecting mem-V ber merges with substantially concave sides into the cylindrical faces of the pistons. Y

3. A reversible planetary piston pump asV claimed in Yclaim l, in which said shaft has a recess and convex axial endl faces, the said recess and faces being so arranged as to make possible circulation Vof liquid, which may have entered all said slots.

4. A reversible planetary piston pump as claimed in claim l, in which the slot of the connecting member and the slots of the walls of the pump casing are coated with guideand roll surfaces of a material resistant to rolling friction.

5. A reversible planetary piston pump as claimed in claim l, in which groove-shaped recesses are provided at the inlet'and outlet open# ings and the impeller carries an elastic coating having sealing edges thereon said sealing edges being so disposed that when the respective pump pistonris in its inner position the respective edges are in a sealing position in the recesses, the said recesses being deeper than the height of said sealing edges, so that a space for'liquid is obtained in order to moderate the motions of the pump elements.

l 6. 'A reversible planetary piston pump, as claimed in claim 1, in which the extension of the slots in the walls of the pump casing in the plane through the piston axes equals approximately the Sum of the diameter of said shaft plus the radius of the circles about which the centers of the plstons oscillate, the central line of said slots coinciding with the transversal plane through the center of the pump casing.V

7. A reversible planetary piston pump, as

claimed in claim 1,7m which groove-shaped recesses are provided at the inlet and outlet openings and the impeller carries an elastic coating having sealing edges thereon, said sealing edges being adapted to rest in a sealing position in said recesses when the respective pump piston is in its inner position.

GUSTAV RUDOLF' LIN DBERG.

Images