US2545604A

US2545604A - Pump

Info

Publication number: US2545604A
Application number: US644812A
Authority: US
Inventors: Byram Frederick Cameron
Original assignee: Robbins and Myers Inc
Current assignee: Robbins and Myers Inc
Priority date: 1946-02-01
Filing date: 1946-02-01
Publication date: 1951-03-20
Anticipated expiration: 1968-03-20

Description

March 20, 1951 F. c. BYRAM PUMP 2 sheets-sheet 1 Filed Feb. 1, 194e ATTO RNEYS.

March 20, 1951 F` c. BYRAM 2,545,604

MMMllylg/ www ATTORNEYS.

Patented Mar. 20, 1951 UNITED sTATEs PATENT OFFICE PUMP Frederick Cameron Byrain, Springfield, Ohio, as-

signor to Robbins & Myers, Inc., Springfield, Ohio, a corporation of Ohio Application February 1, 1946, Serial No. 644,812

13 Claims. 1

My invention relates to pumps operating on the principle of the U. S. Patent to R. Moineau No. 1,892,217. In pumps of this character in their simplest form there is an hollow external element and within it an internal element, both of them having developed thereon helical contours. The helical contour within the outer member (hereinafter called a stator), in the simplest form is inthe formof two threads, and on the inner member or rotor there is ya, single thread. In the commonest form a cross section of the stator presents a straight sided'oval hole at any point. A cross section of the lrotor at any point presents a circular outlinewhichcorresponds to the ends of the oval. The pitch of the thread in the rotor is half that of the pitch of the threads in the stator. u

In a pump of this character where the stator is held against movement, and the rotor caused to revolve, it is to be noted that the center axis of the rotor must move in an orbital path. The type of pump according to Moineau, which has been used commerci-ally in this country has been driven by means of a universally connected rigid link. Thus, the driving shaft is connected by a universal joint to this link and the link is connected by another universal joint to the end of the rotor. This construction does not have the compactness and mechanical eiiiciency that is most desirable and the object of my invention, among other things, is to provide an improved driving arrangement for the rotor of such a e pump.

bearing surfaces for the rotor construction. In

such a case, the stator itself may be cut with orifices for exit and entrance into the space between the rotor and stator.

I' have illustrated vin the appended drawings, a preferred but exemplary form of my invention, and will describe this in det-ail in order to explain the nature of my invention. In the claims appended to the specication, to which reference is hereby made, will be found a statement of the novel features which are considered to be my invention of which the said disclosure is but an example.

In the drawings: v

.Figure 1 is a perspective view of a complete pump according to my invention.

Figure 2 is a central longitudinal section thereof.

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

Figure 4 is a longitudinal section showing a modification in the structure of my pump.

Figure 5 is a like section showing a second modification.

The stator structure of the pump in the preferred form is made from laminated phenolformaldehyde resin. It has a median circumferential flange I, and an, elongated hollow cylindrical body 2'. 7 The ends 'of this cylindrical body have a serie's'of holes 3v therein for exit of fluid and entrance of fluid with reference to the interior of the hollow body. The interior of the body is formed with a pair of helical threads 4,4 extending throughout. If the holes 3 are omitted, then the thrust plates forthe ,rotor tobe described below m'ay be provided with inliux and efflux orifices. s

I The outercasing of the pump is formed of two heads and 6 which are bolted together through the flange I of the stator. In each head there is formed a threaded opening I for entrance and exit of fluid to the interior. Each head has a ange 8 which is seated against the stator flange, the boltsV or screws 9 passing through matching holes serving to grip the stator ange fast between the two headanges.. Y Y

In the form of pump illustrated the head 5 is different from the head 6. This is not necessary as both heads could be the same, but since the driving shaft must be` provided with a gland of some sort to seal its entrance and it is only necessary to reverse the direction of drive for the rotor, to reverse the direction of operation of the pump, it is considered simpler to have butA one entrance head 5. This head has developed thereon a cylindrical body I0, with a journal for the drive shaft I I therein. I have shown a Vbushing I2 serving as a bearing for the drive shaft at this point. An oil hole and cap I3 provides for lubrication of this bushing. A Sylphon bellow seal I4 is mounted on the shaft and the end of the shaft has a head I5 which is slotted for the reception of a sliding block I6 which may be of laminated phenolic condensation product material, if desired. e

Where the stator has -a double thread, as by developing an oval shaped hole in a helical curve lengthwise thereof, the rotor I'I will have a single thread of one half the pitch length of either stator thread. As already noted, where variations from this standard are followed, the eiiiciency of the device is sacrificed.

As a convenient way of mounting the rotor, it

is cored out and supported by a spindle I 1a. A thimble i8 is threaded on one end of this spindle, said thimble tting the core of the rotor. A flange on this thimble at I9 engages the end of the stator. This ange, which is in eifect a thrust plate on the end of the rotor must move orbitally as well as revolve. By preference the thimble is formed of a hardened metal and is held in place by a nut 18a on the end of the spindle. The drive end of the rotor is equipped in like manner with a head 2li, which has a transverse slot therein as at 2|. The head has a flange 22, also, which bears against the end of the stator. The flange l 9 and the flange 22 constitute thrust bearings for the rotor.

Instead of making the stator of one kind of material as a unit as indicated, it can be built up of different materials secured together. For example, the stator shown could have a bonded rubber core, and a metallic exterior and end pieces for the thrust surfaces.

The sliding block I6 held loosely in the slot of the driving shaft head, also engages loosely in the slot 2| of the rotor head, when the slot in the rotor head is at right angles to the slot in the driving shaft head. As so arranged a universal but purely torsional drive is supplied, and there being no requirement on the driving shaft for carrying the lengthwise thrust on the rotor, this .drive is all that is needed to permit the rotor while it revolves at the same time, to rotate about on its axis, .on an orbit, the clearance of the block .from the slots in which it is placed aiding in permitting this full movement.

There are various possible modications of the particular structure described.

Instead of using the stator flange as part of the casing of the pump it can be employed to secure the stator in other ways. Thus in Figure 4 there is shown a pump .having a casing 3l) with an outlet orifice 3|, which casing is flanged as at 32 and secured thereby to the head 33, which has the entrance orice 34 therein. The flange 35 at one end of the stator 35 is engaged between the casing 3U and a shoulder 37 on the head 33. Also the stator engages a shoulder at 31a on the main casing.

In this instance I have shown a different mode of supplying a pure torque drive to and taking up the thrust of the rotor. Thus the rotor 33 has one end bearing slidably on the adjustable abutment post 39. The rotor has `a flange 4B which engages as a bearing on the margin of an annulus 4l developed in the head 33. The thrust on the rotor is thus taken up in the casing but not by means of bearing on the ends of the stator. This leaves the stator open at both ends for influx and efliux of iiuid during operation of the pump.

In this case I have shown a ball bearing 42 instead of a sleeve or bushing type of bearing for the rotor shaft at one end. As a drive the inner end 43 of the drive shaft, and the flanged end of the rotor are provided with

elliptical recesses

44 and 45 respectively. The margin of the annulus di slidably engages the flanged end of the rotor. A drive link `i8 is provided which is ribbed intermediate its ends and has its ends narrowed to rounded edge blades 49, the ends of which are curved longitudinally thereof. The inner ends of the two recesses are also brought to a fiat sided conformation so as to take a torque engagement on the narrowed `ends or blades of the link. This drive will be a substitute for the type of drive illustrated in the other figures of the drawings, which is known as an Oldham drive. It is immaterial what kind of a single plane torque drive is substituted for the ones shown, and, of course, certain features of my invention are Well adapted for use in pumps which have the normal universal joint connected drive link for the rotor.

In Figure 5 is shown a pump for direct attachment to a drive motor casing. In this instance the drive motor is indicated at 60, and its flanged housing portion at 5I. The motor drive shaft 62 (suitably sealed) projects into a space surrounded by a flanged ring 63 that screws onto the motor housing. The pump rotor Sil, in this `instance takes its thrust in one direction on the motor shaft. The single plane universal drive element G5, which is of the same general construction as that shown in Figure 2, couples the end of the rotor to the drive shaft. 4In this instance the block lEa, corresponding to the block IB of Figure 2-, is apertured as at |619, for the passage of the dumb bell shaped piece 5S, which transmits axial thrust between the drive shaft 62 and the roto-r 64. The other i end of the rotor bears against a round ended plug 6G in the casing. Instead of this rounded plug a thrust structure such as is :shown in the universal drive element B5 may be used. Thus the rotor shaft may be hollowed out as indicated at 51, at both ends, and the drive .shaft coupling and the plug be hollowed lout as at 68 and a dumb bell shaped piece 69 be used as a thrust member at each end of the rotor.

In this instance the stator ila-nge is used in a different way to provide an immovable mounting for the stator. The stator 1i! has a ange 'H which seats on a shoulder 12 in the cylindrical portion .'13 of the pump casing. A ring 13a having ears 74 to receive mounting bolts 15 is bolted in place over the end of the stator ange, holding it firmly on the said seat.

The balance of the pump casing includes a flanged portion 'I6 which is bolted to the ring 63, in which portion is the entrance opening Tl of the pump. The exit opening 'I8 of the pump is in the closed end of the casing. In this case also I have shown a bypass 19 with a spring controlled ball check 30 to maintain the pressure of the exit `of fluids at a controlled value.

From these modifications the man skilled in the art will see various other modes of utilizing the principles of my novel structure, and it is not intended by the inclusion of the forms shown to exclude others or exclude ycombinations containing some but not all of the structures diierently arranged.

It is intended that the claims that follow ex-v press the novelty inherent in the exemplary structures, together with the equivalents thereof.

Having thus described my invention, what yli claim as new and desire to secure by Letters Patent is:

1. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads and so related that to revolve the rotor within the stator enforces an orbital path upon the rotor, a drive for the rotor including a torsion producing element arranged to permit orbital movement of said rotor, means for holding the stator against movement, and an independent thrust member associated with said torsion producing element for absorbing the axial thrust of said rotor, whereby said torsion producing element is freed of axial thrust.

2. The combination of claim 1 in which means is provided for sealing one end of the stator from the other.

3. The combination of claim 1 in which the means for holding the stator comprises a flange on the stator which acts as a barrier between the ends of the stator.

4. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads, the stator having one more thread than the rotor, so that to revolve the rotor within the stator enforces an orbital path upon the roto-r, bearing plates on both ends of the rotor slidably engaging the ends of the stator, and means for holding the stator against movement.

5. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads, the stator having one more thread than the rotor, so that to revolve the rotor within the stator enforces an orbital path upon the rotor, thrust means on the rotor arranged to apply thrust in both directions to the ends of the stator, and means for holding the stator against movement.

6. The combination of claim 5 in which the stator has orifices in its sides adjacent its ends for influx and efflux of fluid to be pumped.

7. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads and so related that to revolve the rotor within the stator enforces an orbital path upon the rotor, bearing plates on both ends of the rotor slidably engaging the ends of the stator; and means for holding the stator against movement, said pump having casing means embracing the stator, said casing means having parts for each end of the stator, a drive shaft journaled in said casing, and a connection between the drive shaft and the rotor having a sliding key between the two parts, thus permitting orbital movement of the rotor while being rotated.

8. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts havinginterengaging helical threads enforcing an orbital path upon the rotor when revolved within the stator, a circumferential flange on the stator intermediate the ends thereof and a casing for the pump comprising two hollow heads embracing the stator, said heads engaging the said stator flange n and xedly held in such engagement, whereby the stator is held against endwise and rotary movement, a rotor spindle and means on the rotor spindle to slidably engage each end of the stator.

9. The combination of claim 1 in which the pump is provided with a casing and the independent thrust member for the rotor is applied to the casing.

10. The combination of claim 1 in which said drive includes a drive shaft, and in which the independent thrust member for the rotor is applied for thrust in one direction at least to the drive shaft for said rotor but independent of the torsion producing element thereof.

11. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads .and so re lated that to revolve the rotor within the stator enforces an orbital path upon the rotor, a drive for the rotor including a torsion producing element arranged to permit orbital movement of said rotor, a circumferential flange on the stator and a casing for the pump comprising two hollow members one of which at least embraces the stator, said members engaging the said flange and xedly held in such engagement for holding the stator against movement, and an independent thrust member associated with said torsion producing element for absorbing the axial thrust of said rotor, whereby said torsion producing element is freed of axial thrust.

l2. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads and so related that to revolve the rotor within the stator enforces an orbital path upon the rotor, a drive for the rotor including a torsion producing element arranged to .permit orbital movement of said rotor, a circumferential flange on the stator intermediate the ends thereof and a casing for the pump comprising two hollow members embracing the stator, said members engaging the said flange and xedly held in such engagement for holding the stator against movement, and an independent thrust member associated with said torsion producing element for absorbing the axial thrust of said rotor, whereby said torsion producing element is freed of axial thrust.

13. In a pump having a hollow cylindrical stator and a rotor therein, the respective parts having cooperating helical threads and so reu lated that to revolve the rotor within the stator enforces an orbital path upon the rotor, a drive for the rotor including a torsion producing elcment arranged to permit orbital movement of said rotor, a circumferential flange on the stator and a casing for the pump, said casing having means for engaging said flange and enclosing said flange at both sides so as to form a barrier between the two ends of the stator on the outside thereof and serving to hold the stator against endwise and rotary movement, and an independent thrust member associated with said torsion producing element for absorbing the axial thrust of said rotor, whereby said torsion producing element is free of axial thrust.

FREDERICK CAMERON BYRAM.

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

UNITED STATES PATENTS Number Name Date 1,892,217 Moineau Dec. 27, 1932 2,290,137 Aldridge July 14, 1942 FOREIGN PATENTS Number Country Date 113,009 Australia Apr. 28, 1941 360,335 Great Britain Nov. 5, 1931 446,291 Great Britain Apr. 27, 1936 534,682 Germany Sept. 10, 1931 780,791 France Feb. 11. 1935