US2525265A - Glandless pump - Google Patents

Description

oct. 1o, 195o R. L L, MOINEAU 2,525,265

GLANDLESS PUMP Filed June 18, 1946 2 Sheets-Sheet 1 IN VEN TOR.

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Oct. 10, 1950 R. J. L. MolNEAu GLANDLESS PUMP Filed June 18. 1946 2 Sheets-Sheet 2 N VE NTOR. 001.5 [ifa/N540.

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Patented Oct. 10, 1950 2,525,265 l GLANDLEss PUMP en Joseph Louis Moineau, Paris, France; Adele Moineau, administratrix of said Ren Joseph Louis Moineau, assignor to Robbins & Myers, Inc., Springfield, Ohio, a corporation of Chio Application June 1s, 1946, serial N6. 677,611 In France September 13, 1945 1 This invention relates to a glandless pump and particularly to a pump operating on the principles disclosed and claimed in my U. S. Patent.

No. 1,892,217 dated December 27, 1932. In that patent I have disclosed a pump comprising a stator and a rotor having respectively internal and external helical threads. The stator element always has one thread more than the rotor element; for example, the stator might have a double thread and the rotor a single thread, or the stator might have a triple thread and the rotor a double thread. As pointed out in that patent, in operation there is a relative rolling motion of the rotor with respect to the stator; thus if the stator is fixed, the rotor will roll around theinside oi' the stator, while if the roto-r is fixed, the stator will roll around the outside of the rotor.

I have discovered that it is possible, by combining two pairs of rotors and stators in a certain manner, to achieve a number of advantages which are not found in ordinary or conventional pumps; and itis therefore an object of my invention to provide a pump comprising one or more pairs of rotors and stators combined in such a manner that end thrust is entirely eliminated. It'

isa further object of my invention to provide such a pump in which stuffing boxes or packing glands are entirely eliminated. It is thus an ancillary object of my invention to provide a pump adapted to the pumping of fluids. such as acids, which will deleteriously affect the conventional stufling box or packing gland, but which can be pumped through my novel pumps without ill effects.

These and other objects of my invention which will be pointed out in more detail hereinafter or which will be apparent to one skilled in the 'art upon reading these specications, I accomplish by that certain construction and arrangement of parts of `which I shall now describe certainiexemplary embodiments.

Reference may be had to the drawings forming a part hereof and in which Figs. 1 and 2 are diagrams which will assist in understanding principles of operation of the pump.

. Fig. 3 is a longitudinal cross sectional view of a pump according to my invention.

"Fig, 4 is a cross sectional view `taken line 4 4 of Fig. 3.

Figljis a longitudinal cross sectional view of a modiiication thereof. y

j Flgl` 6 is a perspectiveview oi still another form on the 10 Claims. (Cl. 103-4) Fig. rI is a cross sectional view line 1-1 of Fig. 6.

Fig. 8 is a cross sectional view on the line 8-8 taken on the of Fig. 9 of a pump comprising a single set of v pumping elements, with a drive having no pumping function.

Fig. 9 is a cross sectional view taken on the line 9 9 of Fig. 8.

A study of my above mentioned patent will assist materially in understanding the present invention. `As indicated diagrammatically in Fig. 1, the mechanism comprises tw'o groups of internal and external gear members with parallel axes. These elements are represented in Fig. 1 by their pitch circles. One group comprises two elements. one rolling within the other, the external element being represented by its pitch circle C1, having its center at Oi and having a diameter D, and the internal element being represented by the circle Cz, having its center at O2 and having a ,diameter d. The second group also comprises two elements, one rolling within the other. Their pitch circles are indicated respectively at Ca and C4 having their centers at 0a and O4 respectively, and having respectively the same diameters D and d as those of the first group.

Let it now be assumed that the internal elements i. e. those having the pitch circles C2 and C4 are rigidly connected as, for example, by a rod R in such manner that the points of tangency of their pitch circles C2 and C4 with the pitch circles C1 and C: are in the same angular positions. In Fig. 1, these points of tangency areindicated at a and b.

If now, one of the groups of gear members (C1 and Cz) is driven in such a way that C1 is fixed, the circle C2 will roll on the interior surface of C1 without slipping. The other group (C3 and C4) ls driven in such a way that the external element C: is caused to move in circular translation (without axial rotation) in the path denoted by the circle C5, having its center at O1 with the internal element C4 rolling within the element Ca without slipping.

It is demonstrable that if C2 turns in the directlon of the arrow fi rolling so that the point of contact is displaced in the opposite direction, the member C1 remaining fixed, the circle C4 will roll within the circle C: in like manner and in the same direction provided that. (l) the circle C3 is given a circular translation in the path C5 and in the direction of the arrow f2 (same direction as f1) and (2) the angle y (position angle of the circle Cs) bears a constant relation to the angle :c (position angle of the circle Ca). The angle :c represents the angle covered by the point of contact of Cz with C1 from the point indicated at a to the point indicated at a1. vThe point on the circle C2 at a has during this movement moved to the position a2 so that the arc aai is equal to the arc azar, and the angles which subtend these arcs, will be related as:

Thus, the result'of driving two gearing elements by two other gearing elements having equal pitch circles, transforms a uniform circular translation into a, uniform rotation, or vice versa, the relation between the angular speeds being equal to The particular gears used may be of any kind and even different from each other, providing that they have equal base circles. If the gears are of the type disclosed in my above mentioned patent, then one or both pairs of gears may act as pumping elements.

Fig. 2 shows diagrammatically some profiles which may be used. These profiles indicated at P1 and P2 are hypocycloids of the pitch circles Ce and C1. The external element Cs has one more thread than the internal element C1. In this case, the number of threads is respectively 3 and 2, and in general, if n is the number of teeth of the internal element, then' d D-d-"n-I-l-n- Thus, in Fig. 2 we have nso that Referring to Fig. 3, if the elements II) and II constitute a pump or compressor, they can be driven by a gearing I2, I3 which could be of any type, helical or not, and having any number of teeth, provided they have the same pitch circles as those of the gears I0, II.

Instead of using conventional gearing for this drive it is possible to use another pair of pump elements which are in effect gears. This arrangement is illustrated in Figs. 3 and 4 where I have shown a multi-cylinder` pump having four pairs of pump elements driven by another four pairs of pump elements. The pump elements are connected in sets'as seen in Fig. 3 and equally distributed around the central axis of the pump. as seen in Fig. 4. The four pairs of gears I2, I3 are connected together in a spider like mounting Il, mounted'by means of bearings I5 on a crank shaft I6. The members II and I3 of the sets of pump elements are rigidly connected together by the bent hollow shafts which act as cranks having an eccentricity equal to that of the crank shaft. I6. Because of the connections described, when rotation is imparted to the crank shaft I6, the members I2 will be given a circular translation but will not be permitted to rotate.

From the foregoing, it will be clear` that as the assembly indicatedv generally at Il follows the circular translation about the central axis of the pump, the cranked hollow shafts 20 will be caused to rotate and the members I3 and II will roll respectively within the elements I0 and I2.

'I'he elements I2, I3 have a helical thread of opposite hand from that of the members I0 and II so that the fluid being pumped entering the intake port at 2|, will be divided. That portion being pumped by the elements I0, II, passes through these gears to the discharge port 22; at the same time, that portion being pumped by the elements I2, I3, passes to the right through c. the space between the sleeve I1 and the hollow shaft 20, is pumped toward the right by the elements I2, I3 into the chamber I4a. From here it passes back toward the left through the g hollow shaft 20 and joins that portion which is being pumped by the members I0, II, both portions passing out through the port 22. In Figure 3 the sleeve I1 is shown as a piece of rigid tubing mounted between diaphragm members I8 and I9.

The members I8 and I9 having to contend with considerable pivotal action resulting from thc orbital movement have to be made of a thick rubber-like material. It would, of course, be possible for the parts I1, I8 and I9 to be constituted of a resilient material'molded in a single piece. The space between the sleeve I1 and the hollow offset shafting 20 contains liquid under suction pressure moving in the direction of the arrows from left to right between the shaft 20 and sleeve I1. A study of Fig. 3 in connection with the foregoing description will demonstrate that in this pump, end thrust is entirely eliminated except for that resulting from the passage of fluid through the hollow shaft 20, and that the pump requires no packing glands or stuillng boxes whatever.

A variant is shown in Fig. 5 in which as above, there are four sets of pumping elements, but both sets are flxed. The rotors are driven by a centrally disposed helical gearing, which in this case functions simply as a gear and not as a pump. The stators 23 are all fixed in the housing relative to each other and each pair of axially aligned rotors 24 are connected by the crank portions 25 which are provided with an internal helical gear element 26. The four elements 26 each roll in external elements 21 and the four members 21 are carried in a spider arrangement about a central bearing 28. The drive shaft 29 has a central crank portion 30 by means of which the assembly of four gear pairs 26, 21 is given a circular translation, whereby the cranks 25 are caused to rotate, driving the rotors 2| of the eight pumping pairs. Since the members 26, 21 donot have a pumping function, the length of these members will preferably be equal to at least a fraction of the pitch of a gear member equal to said pitch divided by the number of threads of said member, as pointed out in my above mentioned patent. In fact the members 26, 21 could be gears of any type and having any desired number of teeth provided the relationships above mentioned obtain. This pump has a completely balanced end thrust, since fluid entering the inlet port is pumped outwardly through all eight pumping pairs into the manifolds 32 from which it passes to the exhaust port 33. It is also possible by reversing the rotation of the mechanism to have the fluid enter port 33 and discharge through port 3|. The shaft 29 is enclosed by fluid tight tubes 34 which are either wholly flexible or are rigid in nature and are then fastened at each end by means of flexible bellows-like members 36 and 36, so that again the pump of Fig. 5 requires no packing glandsor "atrasos stumng boxes. In the embodiment of Fig. 5, the gears 26, 21 may be compared, as to their driving functions, to the members i2, |30! Iiig.v 3.

In Figs. 6 and 7, I have shown avcommercial embodiment oi' the principles described above in which there is a single set oi pumping elements. The external element 40 is fixed in the housing 4I and the internal element 42 will roll around the inside 4of the member 40. The internal member 42 is fastened to or is integral with the internal member 43 of the other pair of pumping elements and the members 42 and 43 are off-set to provided the necessary cranking action. The members 42 and 43 are provided with an internal iluid passageway 44 extending from the exterior end of member 42 to the exterior end of member 43. The external element 45 cooperating with the internal element 43 has a bearing indicated generally at 46 in the cup like element 41. The member 41 is driven by the motor 48; and there it should be noted that the axis of the bearing 46 is eccentric with respect to the motor axis s o that the member 41 rotates in a circular path about the motor axis. Since the external element 45 is xed in the member 49 which has its bearing at 46 and since the member 49 is prevented from rotation by the sleeve 50 and the diaphragms 5|, it will be clear that the member 45 will be translated in a circular path without rotation. Ifthe relationships described above are observed, the portion 43 will roll around the inside of the member 45 while the portion 42 rolls around the inside of the fixed element 40. Fluid entering the intake port 52 is pumped toward the top by the elements 40, 42 and toward the bottom of the elements 43, 45. The portion of the iluid pumped by the elements 43, 45 is returned to the top through the bore 44 and all the fluid emerges at the exhaust port 53.

In Figs. 8 and 9, I have illustrated a modified construction in which there is only a single pair oi.' pumping elements, and the drive elements are not even gears, although they produce the correct motion required for the pumping elements.

The pumping elements are indicated at 60 and 6|, the element 60 being fixed in the housing 63.

member 6| is provided with the crank member 65 as was the case in all the other examples. As a drive for the member 6|, I have provided the' member 66 mounted on a drive shaft B1, and having an internal circular bearing cup 68 which is eccentric to the shaft 61.

In the cup 68, I-mount a circular block 69, having two slots at right angles to each other and at different depths, as shown at and 1I. Cross-heads 12 and 13 ride in these slots and are provided with bearing sockets 14 and 15, in which ride the pins 16 and 11 which are integral but eccentric to each other, and are connected to the crank 65. The block 69 is held against 4axial rotation by the universal rods 18 as shown.

As the shaft 61 rotates, the cup 68 moves in a circular path because of its eccentricity, and the block 69 is carried ina circular path without rotation because of the members 18. The parts 10, 1|, 12, 13, 14, 15, 16, and 11 function in the same manner as, for example, the members I2, I3 of Fig. 3. They can, in fact, be considered as cross sectional elements of a pair of members such as i2, I3, taken a quarter stator pitch length apart.

From the foregoing description, it will be understood that I have provided a glandless pump,

balanced against end thrust'and also dynamically balanced in rotation by the counterweight 54 (see Fig. 7) .v It will be clear-that numerous modiilcations may be made without departing` from the spirit of my invention and that I dovnot intend to limit myself except as pointed out in the claims which follow.

For convenience and clarity in the claims:

(1) The term "gear pair" means an internal and an external khelical ygear in meshing relation, wherein the external gear has one more thread than the internalsear, and the diameters of the pitch circles of said gears are in proportion to the number oi' threads;

(2) The term "gear set means two gear pairs, the internal gears of which are interconnected;

(3) The term pumping gear pair" means a gear pair which has a pumping function;

(4) The term "driving gear pair means a gear pair which induces movement in another gear pair, and which may or may not have a pumping function.

Havingnew fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A gear train comprising at least two gear pairs the axes of the gears in said pairs being parallel, the pitch circles of the external gears being equal and the pitch circles of the internal gears being equal, and said internal gears of the respective gear pairs being rigidly connected together so that their orientation with respect to their respectiveexternal gears is the same, the external gear of one of said pairs being fixed, and means for imparting to the external gear of the other of said pairs a circular translational movement.

2. A mechanism according to claim 1 in which one of said gear pairs is a pumping gear pair.

3. A mechanism according to claim 1 in which both of said gear pairs are pumping gear pairs.

4. A mechanism according to claim 1 wherein the gear pairs are of opposite hand.

5. In a pump, at least one gear set of two gear pairs, the gears of said pairs having parallel axes, the internal gears ofeach gear set being rigidly connected together in mutually eccentric relationship. one of the external gears being xed in space, and means for imparting to the other of said external gears a circular translation, the external gears of said pairs having equal pitch circles and the internal gears of said pairs having equal pitch circles, and the pitch circles of said external gearsvbearing a relation to the pitch circles of said internal gears such that where n is the number of threads of said internal gears, d is the pitch diameter of said internal gears and D is the pitch diameter of said external gears, and the connection between said internal gears being Such that their orientation with respect to their respective external gears is the same.

. 6. In a pump, at least three gear sets, all of the gears of said sets having parallel axes, said gear sets being symmetrically distributed about the central axis of said pump, the internal gears of each of said sets being rigidly connected together in eccentric relationship, one external gear of each of said sets being fixed in space, and means for imparting to the other external gears of said sets a circular translation, the external gears of said sets having equal pitch circles and amma- 7 the internal gears of said sets having equal pitch circles, and the pitch circles of said external gears bearing a relation to the pitch circles of said internal gears such that I where n is the number of threads oi' said internal gears, d is the pitch diameter of said internal gears and D is the pitch diameter of said external gears, and the connection between said internal gears being such that their orientation with respect to their respective external gears is the Same.

7. In a pump according to claim 6 a drive shaft constituting said imparting means and having a crank portion, a spider mounted on said crank portion, said spider carrying said external gears which are not ixed in space.

8. In a pump according to claim 6 a sleeve connecting said external gears, said rigid connection being enclosed in said sleeve, whereby saidpump requires no packing glands. l 9. In a pump comprising at least three gear `sets wherein all of the gears of said sets have parallel axes, said sets being symmetrically disfluid-tight sleeve whereby said pump requireslin packing gland.

10. In a pump according to claim 9 in which said transmitting means comprises a number of driving gear pairs, the number of said driving gear pairs being equal to the number of said sets, the internal gears of said driving gear pairs being constituted by said first mentioned crank member, and the external gears of said driving gear pairs being mounted on a spider having a bear' ing on the crank portion of said drive shaft whereby the external gears of the driving pairs are given a movement of circular. translation. REN JOSEPH LoUrs MoINnAU.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 1,892,217 Moineau Dec. 27, 1932 2,028,407 g Moineau Jan. 21, 1936 2,269,189 Dawns Jan. 6, 1942 2,290,137 Aldridge July 14, 1942 2,329,386 Brennan Sept. 14, 1943 2,381,695' Sennet Aug. 7, 1945 2,399,008 Doran Apr. 23, 1948 'I FOREIGN PATENTS Number Country Date 111,901 Australia Nov. 7, 1940 113,009 Australia Apr. 28, 1941 425,447 Great Britain ,Mar. 14, 1935 Great Britain Oct. 18, 1935

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