US3065705A

US3065705A - Pump with flexible bladed rotor

Info

Publication number: US3065705A
Application number: US83059A
Authority: US
Inventors: Harry J Sadler; Ernest E Cook
Original assignee: HYPRO ENGINEERING Inc
Current assignee: HYPRO ENGINEERING Inc
Priority date: 1961-01-16
Filing date: 1961-01-16
Publication date: 1962-11-27
Anticipated expiration: 1979-11-27

Description

Nov. 27, 1962 H. J. sADLER ET AL 3,065,705

PUMP WITH FLEXIBLE BLADED RoToR Filed Jan. 16, 1961 I7 45 43 l E 47 /07 /5' la Fl E'. l

l /05 mi,5

INVENTORS Haney .7' Seau-'2 By 7u/tsr El Coax rroxwer ited States ae This invention relates to pumps and more particularly to an eccentric rotary displacement pump of the large volume, low pressure type. l An important object of this invention is to provide an eicient and inexpensive pump having exible blades which experience a minimum of fatigue and friction during operation.

Another object of this invention is to provide a rotor having individually removable resilient blades, each of which is so designed as to exert a good working pressure with the walls of the pump chamber at both maximum and minimum flexure and Without creasing or rupturing.

, A still further object is to provide a seal ring which is so positioned on the rotor as to co-operate with the blades in forming a tight seal `against the inner walls of the pumping chambers.

A still further object is t-o provide a port means which has a greater access area to the pumping chambers thereby allowing a large volume of pumping.

These and other objects and advantages of our invention will more fully appear Ifrom the following description, made in connection with the accompanying drawing, wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIGURE 1 is a side sectional view of the pump with various elements thereof in full line drawing, the cross section being taken at 1 1 of FIGURE 2;

FIGURE 2 is a cross sectional end view of FIGURE l taken at 2 2 and further having a portion in cross section to reveal the relation between the rotor structure and the impeller blades; and

FIGURE 3 is a cross sectional View taken at 3*-3 of FIGURE 2 having portions thereof eliminated beyond the broken line.

Referring now more particularly to FIGURE 1, the pump referred to generally as 10, is shown in cross section thereby revealing the principal elements of the pump such as the eccentrically positioned rotor assemblage 11 and the housing 12 consisting of shell 13 and the supporting mount 14.

Forming the shell 13 is an integrally cast annular wall 15, a shell side wall 16, and an annular flange 17. The inside running surfaces 18 of annular wall 15 and shell side wall 16 are, of course, machined to a smooth surface to reduce rotor blade friction to a minimum as will be come evident subsequently.

As shown in FIGURE 1, the side wall 16 has an annular extension 19 at right angles to the side wall 16 and has a smooth continuous surface joint 20 therebetween. Extension 19 further has a bore 21 for receiving in frictional contact a sleeve 22 which in turn has an internal bore 23 to receive the rotor shaft. Sleeve 22 also has an opening 24 which communicates the lubricant admitted by way of grease -tting 25 to the rotor shaft. Also forming a part of the shell side wall is an annular recess 26 for seating the rotary seal 27.

Annular flange 17, as may be seen in both FIGURES 1 and 2, has a plurality of threaded mounting holes 28 so that the shell 13 may be drawn tightly to the supporting mount 14 along `facing 29. Forming a continuous portion of the inside running sur-face 18 of annular wall is annular groove 30 for receiving resilient O-ring 31 for sealing purposes.

Referring now .to the supporting mount 14, a tubular extension 32 is provided for supporting of the rotor shaft and is formed at right angles, and as an integral part, with a smooth continuous joint 33, with the supporting mount side wall 34. Again, as in the annular extension 19, the tubular extension has a bore 35 axially aligned with annular extension bore 21, which frictionally receives a sleeve 36. Sleeve 36 similarly has an internal bore or running surface 37 for receiving a rotor shaft and an opening 38 to communicate lubricant from the grease fitting 39 to the running surface 37 between the sleeve 36 and the rotor shaft. Forming a part of the tubular extension is annular recess 40 for receiving rotary seal 41. Side wall 34 has a smoothly machined inner surface 42 for reducing the running friction between surface 42 and the rotor lblades to a minimum as explained above.

Also forming a part of the supporting mount 14 is an annular iiange 43, mating with that of flange 17, which has an annular recess or notch 44 which in turn has a face surface 45 and outer surface 46. Located in Harige 43 are holes 47 -for loosely receiving bolt 48 and are corresponding in number and position to those of threaded holes 28 of ange 17. Positioned between the bolt head 49 and the outer face 50 of flange 43 is a washer 51.

Forming a part of the supporting mount 14 are inlet connections 52 and outlet connection 53, as more clearly seen in FIGURE 2, which communicate with the inside of the pump by way of inlet port 54 and outlet port 55 respectively. The ports 54 and 55, it will be noted, are divided into two ports i.e. a kidney shaped opening 56 and an elongated teardrop configuration opening 57 separated by a structural membrane 56 which in turn has a front surface 59 flush with, and a part of, inner surface 42, and a rear surface 60, dening a thickness therebetween equal to that of the supporting mount side wall 34 as seen at 61 in FIGURE 1.

As seen in FIGURE 1, a cast passageway 62 connects the inlet ports 54 (FIGURE 2) to the inlet connection 52. As may also be seen in FIGURE l, the port openings 56 and 5'7 extend rearwardly to upper juncture 63 and lower juncture 64 which join upper wall 65 (FIGURE 2) and lower wall 66 respectively to the edge of passageway 67. Passageway 67 in turn resolves into the circular opening 68 to conform to the inlet connection 52.

As shown in FIGURE 2, the kidney shaped openings 56 have similar dimensions on

rounded ends

69 and 70 and sides '71 and 72 except that they are formed at different radii from a common eccentric center point '73. However, the teardrop openings 57 have dissimilar ends, end 74 being smaller than end 75 since edge 7 6 is on a radius of center '73 and edge 77 is on a radius of center point 76.

To provide the pump 10 with the required mounting support, a base 79 having a recess 80 is provided with mounting holes 81 located therethrough. Abutting the base '79 and cast passageway 62 for structural support is vein 82.

Referring now to the rotor assemblage 11, we provide a rotor shaft 83 having one end 84 jounraled into annular extension 19 and the other end 85 journaled through tubular extension 32 beyond which is a short taper S6 to a reduced size shaft extension 37 for connection to an external power source, not shown.

Intertting about the shaft 83 is a unitary cast hub 88 which is secured to the rotor shaft 83 by the co-operation of a set screw 89 and two annular knurled rings 90 encircling shaft 83. The rings 96 provide a highly frictional surface to grip the hub 88 once set screw S9 is tightened whereby positive driving motion is imparted from the shaft 83 to the hub 88.

Interposed between the

ends

91 and 92 of hub 88 and

side wall surfaces

18 and 42 are resilient spacer washers 93 concentrically positioned about shaft 83 and having outer and inner faces 94 and 95 respectively.

Forming a part of hub 88 are radial projections 96 and 97 (FIGURE 2) extending outward to define tapered slots 98 having

edges

99 and 100 converging from slot base 101 along

projections

96 and 97, to

ends

102 and 103 respectively. Forming a supporting structure between

adjacent projections

96 and 97 are rib supports 104. As may be more readily seen in FIGURE 3, the rib supports 164 have a longitudinal taper which converges from a low point 105 on either

end

91 and 92 of hub 88, to the raised point or rib base 106 of the center of the projection. The rib progressively decreases from the rib base 106 to the

radial projection ends

102 and 103 as shown in FIGURE 2.

Referring to FIGURES 1 and 2, we show a plurality of outwardly extending blades 107 having a progressively tapered thickness, dened by side edges 108 and 109, from the inner end 110 to the outer end at point 111 where the abrupt V-shaped taper 112 begins.

Sides

113 and 114 of the V-shaped taper converge to form a blade tip 115. The purposed of this V-shaped taper will be explained subsequently.

As may be seen in FIGURE l, the ends 116 and 117 of the blades are in close clearance with

sides

18 and 42 of

side walls

16 and 34. As will be noticed in FIGURE l, the inner end 110 of blade 107 abuts against the outside edge 118 of spacer washer 93.

Referring to the above description and drawing, a more functional description will now be made of our improve` ments over that of the prior art of rotary pumps.

As set forth in considerable detail above, we provide our supporting mount side wall 34 with both an inlet and outlet porting arrangement consisting of a kidney shaped opening and a teardrop opening separated by a thin structural membrane therebetween. We have found that by providing the side 71, of the kidney shaped opening, at a radius, from eccentric center 73 of the rotor, equal to that of the low point 105 of rib supports 104, that the maximum amount of port opening is provided which will be consistent with other co-operating elements ofthe pump rotor. We have also found that the teardrop opening 57 acquires a natural shape consistent with the pumping process. As will be noted from FIGURE 2 of the drawing, and the direction of rotation of the rotor, the blades 107 will increasingly unflex as they pass over the inlet ports 54. As the blade 107 approaches the position where maximum drawing force is exerted, it will be noted that the teardrop port gets increasingly larger in cross section. As the blade revolves to its maximum extended position, the teardrop port also reaches its maximum size thereby allowing a free llow of iluid into the pumping chamber. As the blade 107 continues around the outlet port 55 is encountered where the maximum port opening i.e., the lower end 75 of teardrop opening 57, is provided for the initial surge of fluid to be discharged. As the blade further rotates and is llexed, the liquid remaining in the chamber is forced out of the pumping chamber toward the smaller end 74 of teardrop opening 57. Since the majority of the pumping or discharging action has taken place by the time the blade 107 approaches end 74 of the teardrop opening, the reduced size of the opening will easily accommodate the residual discharge. Of course, kidney shaped opening 56 is accessible at the same time for discharge from the chamber, as well as teardrop opening 57. Teardrop opening 57, therefore, acts as a gradient for discharge of the luid according to the position of the blade.

The next important feature of our invention is the means by which we reduce, to a minimum, the volume required for structural support of the blades as they are flexed under the eccentric rotation of the rotor. As described above, and shown in FIGURE 3, we simply provide a raised portion or rib between the external sides of adjacent slots. The rib has a maximum dimension at the juncture 106 of adjacent sides and gradually decreases toward the upper ends of the

sides

102 and 103. By providing such a rib support, the radial length of the slots may be shortened thereby allowing a longer portion of the resilient blade to llex upon rotation of the rotor. Although more of the blade is free to flex, the pumping pressure is not appreciably reduced since the taper of the blades, as will be described, holds the blade to an outwardly extending tendency.

As also described above in the description we provide a pair of seal rings or spacer washers 93, one at either end of the rotor hub interposed between the rotor hub 88 and the pump side walls 16- and 34. We find that this seal ring provides a soft sealing surface against the side wall when the rotor is in rotation and it is also readily replaceable upon wear out. The spacer washer is of sullcient diameter so that the outside edge will be in riding contact with the butt or base end 110 of the blades. The result of using these seal rings will be that of completely sealing the pumping chamber and thereby preventing leakage.

The blades themselves are, as shown, individually cast pieces of resilient material having a consistent tapered thickness from the inner end 110 toward the outer end 111. Because the blades are individually cast, they may be readily replaced, as can the spacer washers, whenever the blade becomes worn or fatigued.

By providing a plurality of slots which have an internal taper comparable to that of the blades, the mere operation of insertinga blade in the slot opening will lock the blade in such a position and preventitfrom appreciably dislodging outwardly upon rotation ofthe rotor. We have found that the taper of the blade is a very important feature, for when so tapered, the blade possesses a much more positive pressure holding characteristic. If the blades are not tapered, they must necessarily be of such a great thickness to withstand pumping pressures that there is a high fatigue and friction factor and if they are too thin, they will not hold the pressure of the pumping chamber. Therefore, we have combined the two desired properties into the one impeller blade.

Because the blades are individually cast and individually inserted, it is obvious that upon their removal, any one of the blades or any combination of the blades may be replaced or reversed in the slots thereby restoring the pumping capabilities of the rotor to its original state.

It will, of course, be understood that various changes may be made in the form details, arrangements and proportions of the parts without departing from the scope of our invention as set forth in the appended claims.

What is claimed is:

l. A rotary displacement pump comprising a housing having an annular Wall and axially spaced at side walls, said housing having spaced inlet and outlet ports, a rotor assemblage disposed within said housing, said rotor assemblage having a shaft journaled in said housing across said flat side walls and eccentric with respect to the annular wall, said assemblage having a unitary cast hub secured to said shaft, a plurality of projections extending radially outward from said shaft and forming a part of said cast hub, said projections each having a slot extending radially and laterally outward therethrough, said slot having opposed sides which are convergent radially outward, a corresponding plurality of individual resilient blades, one of said blades being mounted in each of said slots and radially extending outward thereof with a convergently tapered thickness, said blades further having their inner end portions interfitted in said slots and an outer end portion riding in resilient pressing contact with the inside of said annular wall, and the side edges of said blades riding in engagement with Said `side walls whereby to form pumping chambers in communication with said inlet and outlet ports when each of said resilient blades is successively exed due to the eccentric rotation of said rotor.

2. A rotary displacement pump comprising a housing having an annular wall and axially spaced flat side walls, said housing having spaced inlet and outlet ports, a rotor assemblage disposed within said housing, said rotor assemblage having a shaft journaled in said housing across said at side walls and eccentric with respect to the annular wall, said assemblage having a unitary cast hub secured to said shaft and peripherally having a plurality of radially extending projections, each of said projections having a slot extending radially and laterally outward therethrough, said slot having opposed sides which are convergent radially outward, a corresponding plurality of individual resilient blades, one of said blades mounted in each of said slots and radially extending outward thereof with a convergently tapered thickness, said blades further having their inner end portions intertted in said slots, and an outer end portion riding in resilient pressing contact with the inside of said annular wall, the side edges of said blades riding in engagement with said side walls whereby to form pumping chambers in communication with said inlet and outlet ports when each of said blades is successively flexed due to the eccentric rotation of said rotor, said rotor assemblage further having resilient spacer washers concentrically positioned about said shaft and in intertting contact between the end of said rotor and said side walls and further having the periphery thereof in abutting contact with a portion of said inner end portions of said blades.

3. A rotary displacement pump comprising a housing having an annular wall and axially spaced flat side walls, said housing having spaced inlet and outlet ports, a rotor assemblage disposed within said housing, said rotor assemblage having a shaft journaled in said housing across said flat side walls and eccentric with respect to the annular wall, said assemblage further having a unitary cast hub secured to said shaft and peripherally having a plurality of radially extending projections, each of said projections having a slot extending radially and laterally outward therethrough, said slot having opposed sides which are convergent radially outward, a corresponding plurality of individual resilient blades, one of said blades mounted in each of said slots and radially extending outward thereof in a convergently tapered thickness, said blades further having their inner end portions intertted in said slots and lateral ends riding in engagement with said side walls and further having an outer end terminating in abrupt V-shaped tapers whereby the side of said V-shaped 4tapers will have riding engagement with said annular Wall thus to form pumping chambers in cornmunication with said inlet and outlet ports when each said blade is llexed due to the eccentricity of said rotor shaft.

4. A rotary displacement pump comprising a housing having an annular wall and axially spaced ilat side walls, -said housing having spaced inlet and outlet ports, a rotor assemblage disposed within said housing, said rotor assemblage having a shaft-journaled in said housing across said llat side walls and eccentric with respect to the annular wall, said assemblage having a unitary cast hub secured to said shaft and peripherally a plurality of radially eX- tending projections, each of said projections having a slot extending radially and laterally outwar-d therethrough, said slot having opposed sides which are convergent radially outward, a corresponding plurality of resilient blades, one of said blades mounted in each of said slots and radially extending outward thereof in a convergently tapered thickness, said side walls and adjacent blades forming pumping chambers in communication with said inlet and outlet port-s, said rotor assemblage further having resilient spacer washers concentrically positioned about said shaft yand in interlitting contact between the ends of said rotor housing and said side walls and further having an outer periphery thereof in abutting contact with a portion of said radially extending blades,

5. A rotary displacement pump comprising a housing having an annular wall and axially spaced fla-t side walls,

6 assemblage disposed within said housing and having rotor ends adjacent said flat end walls, said rotor assemblage having a shaft journaled in said housing across said flat side walls and eccentric with respect to the annular wall,

said assemblage having a unitary cast hub secured to said shaft and peripherally having a plurality of radially extending projections and integrally cast structural rib supports therebetween, said rib supports being formed by a longitudinally convergent raised portion intermediate of 1() said rotor ends and having a lower portion of said rib supports substantially suppressed radially at both rotor ends, each of said projections further having a slot extending radially `and laterally outward therethrough, said slots having opposed sides which are convergent radially outward, a corresponding plurality of resilient blades, one

of said blades being mounted in each of said slots and radially extending outward thereof in a convergently tapered thickness whereby to form pumping chambers when each of said blades is successively flexed due to the eccentric rotation of said rotor.

6. A rotary displacement pump comprising a housing having an annular wall and axially spaced flat side walls, one of said walls having inlet and outlet ports, a rotor assemblage disposed within said housing having ends adjacent said flat side walls, said rotor assemblage having a shaft journaled in said housing across the flat side walls and eccentric with respect to the annular wall, resilient spacer `washers concentrically positioned about said shaft and in interfitting contact between the ends of said rotor and said end walls, said assemblage further having unitary cast hub secured to said shaft and peripherally having a plurality of radially extending portions and integrally cast structural rib supports therebetween, said rib supports formed by a longitudinally convergent raised portion intermediate of said rotor ends and having lower portions thereof substantially depressed radially at both ends to the outer periphery of said spacer washer, each of said projections further having Ia slot extending radially and laterally outward therethrough, said slot having opposed 0 sides which are convergent radially outward, a corresponding plurality of individual resilient blades, one of said blades being mounted in each of said slots and radially extending outward thereof in a convergently tapered thickness, said blades further having the lateral ends thereof coplanar with said spacer washers thus forming a comto the annular wall and one of said ilat side walls further having an inlet port and an outlet port, said rotor assemblage and said housing forming a plurality of pumping chambers communicating with said inlet and outlet ports, said port-s being arcuately shaped and individually divided 30 into va plurality of openings by a web, one of said openings having an inner arcuate shape of constant width and another of said openings having a varying width defined by sides, one of which lies on a given radius of said rotor center and the other of which lies on a given radius of said annular wall center.

8. A rotary displacement pump comprising a housing having an annular wall and axially spaced ilat side walls, a rotor assemblage disposed within said housing, said rotor assemblage having a shaft journaled in said housing across said iiat side walls and eccentric with respect to the annular wall, said rotor assemblage further having a unitary cast hub secured to said shaft and peripherally having a plurality of radially extending projections and integrally cast structural rib supports therebetween, said said housing having spaced inlet and outlet ports, a rotor rib supports being formed by a longitudinally convergent raised portion intermediate of said rotor ends and having a lower portion of said rib supports substantially suppressedrradially at both rotor ends, and one of said flat side walls further having an inlet port and an outlet port, the length of said ports ibeing defined by a radial are and having one side thereof dened by a given radius having a common center point with that of said radial are and said rotor shaft and further having said side of substantially equal radial distance from said common center as that of the lower portion of Said unitary cast hub ribs, whereby said rotor assemblage and said housing form a plurality of pumping chambers in communication With said inlet and outlet ports.

References Cited in the ie of this patent UNITED STATES PATENTS Roth Dec. 30, Simer, et al. Feb. 8, Kiekhaefer Apr. 5, Dinesen et al. Jan. 3, Ferris Mar. 24, Sherwood July 15, Sully Mar. 28,

FOREIGN PATENTS Germany Feb. 25,