US2075843A - Fluid pump - Google Patents

Description

April 6, 1937; H. J. GERDAU 2,075,843

FLUID PUMP Filed Deo. 9, 1935 2 Sheets-Sheet l ATTORNEY.

April 6, 1937- H. J. GERDAU `2,075,843

' FLUID PUMP Filed Dec. 9, 1935 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Patented pr. 6, 109037 UNITED STATES` PATENT `OFFICE 7 Claims.

'I'his invention relates generally to displacement devices such as arev employed for pumping various fluids. More specifically it relates to pumps of the type which'utilize a rotatable assembly, consisting of an impeller having radially extending vanes, in conjunction with an eccentrically mounted rotatable drum.

It is an object of the invention to provide a pump of the above type which is capable of long useful service without undue wear on the working parts, and which affords smooth operation without undue noise or vibration.

It is a further object of the invention to provide a pump capable of successful operation where high suction or pressure heads are required, and which can be substituted for more complicated and expensive pumping equipment now available on the market, as for example, in place of multiple stage centrifugal pumps.

Further objects of the invention will appear from the following description of which the preierred embodiment of the invention has been set forth in detail in conjunction with the accompanying drawings.

Refer-ring to the drawings:

Fig. 1 is a side elevational view, in cross section, illustrating a pump incorporating the present invention.

Fig. 2 is a cross sectional detail, taken along the line 2-2 of Fig. 1.

Fig. 3 is a cross sectional view, taken along the line 3--3 of Fig. 2.

Fig. 4 is a perspective detail, showing two segmental members and their journal rings.`

Fig. 5 isa perspective detail of the fixed segmental member.

The pump illustrated in the drawings consists of a housing I0, provided with inlet and outlet openings II and I2. For convenience one side Wall I3 of the housing is made removable, and is shown being secured to the main body of the housing by suitable means, such as cap screws I4. The other side wall I6 can be made removable, or integral with the main part of the housing as illustrated. Disposed within the housing there is a rotor assembly which includes. the drum I1 and the impeller I3.

The impeller I8 consists of hubs I9, carrying radially extending vanes 2i. The drive shaft 22 upon which the impeller is mounted, extends through the housing, and is journalled by suitable means such as the journal blocks 23 and 20.

It will be noted from Fig. 1 that these journal.

blocks are seated in the side walls I3 and I6 of the housing, and that they may be removably re- (Cl. 10S-144) tained in such position by suitable means, such as cap screws 26 and 21. Suitable packing glands 28 and 29, can be provided to prevent leakage about the shaft. If desired, the shaft can also be provided with a. supplemental external bearing 3 I, which is shown being supported by the side of the housing. A

The drum I1 is cylindrical in contour, as illustrated in Fig. 2, and includes the peripheral wall portions 32, in conjunctionV with the vend walls 33 and 34. Instead of forming the drum as one integral structure, it is desirable to form it in two sections Ila and I1b, with the peripheral wall portions of the two sections fitted together, as indicated at 36 in Fig. 1. Suitable means are provided for retaining the two sections clamped together, as will be presently explained.

Referring to Fig. 2, it will be noted that .the periphery of the drum is interrupted by a slot 31, which accommodates one of the vanes 2|, and

by additional elongated slots 38, whichaccommodte the 'remainder of the vanes. The impeller vane which operates through slot 31, has a positive drive connection with the drum, which can be formed as fol1oWs:-Mounted adjacent the inner periphery vof the drum there is an arcuate block 39, which serves as a journal for a pin 4I. 'I'his pin 4I is provided with a lateralslot 42, to slidably, accommodate the associated impeller vane -2I. vThe block 39 is also cut away as indicated at 43 and 44, to enable a certain latitude of turning movement of the impeller, as permitted by rotation of pin 4I about its axis. The side faces of the block 39 are secured to the adjacent side walls of the drum I1, by simple means such as screws 46, thus not only retaining the block 39 in proper position, but also incidentally serving as means for retaining the two sections of the drum together. Near the opposite side of the drum, the two drum sections can also be secured together by means of a bolt 41. It will be evident that while the impeller associated with slot 31 may move outwardly and inwardly by sliding movement through pin 4I, and may also have relative turning movement with respect to the drum about the axis of rotation of pin 4I, a positive torque transmitting drive connection is actually established between the impeller and the The drum I1 is mounted for rotation about an axis eccentric with respect to the axis of rotation of the drive shaft 22. While the particular manner in which the drum is journaled may vary in practice, the arrangement illustrated is as followst-Sleeves 5I and 52 have a force fit within the end walls 33 and 34 of the drum. These sleeves are in turn journaled upon the blocks 23 and 24, whereby the drum may rotate about an axis parallel to the axis of the shaft 22, but spaced therefrom by a definite amount of eccentricity.

If adequate means were not provided for properly retaining the segmental members 48, they would be pressed outwardly by centrifugal force against the inner peripheral walls of the drum, thus causing considerable frictional loss, in addition to causing excessive wear. The novel means which I utilize for the mounting of these members serves to retain their outer faces slightly spaced from the inner peripheral surface of the drum, and at the same time limited oscillating movement is permitted, relative to the drum and about the axis of rotation of the drum. The means illustrated for this purpose consists of pairs of journal rings 53 and 54 (Fig. 4), to which the segmental members 48 are secured. By reference to Figs. 2, 3, and 4, it will be. noted that each ring 53 is secured to its associated segmental member 4B, by means of a web-like arm 56, while each ring 54 is likewise secured to its associated segmental member by a web-like arm 51. With a pump of this type illustrated, in which the impeller consists of only three equally spaced vanes, there are two sets or pairs of the ring 53 and 54. It is desirable to have these rings directly journalled upon the sleeves 5I and 52, and in order that they may not interfere with proper operation of the impeller, it will be noted that they are located beyond the side edges of the impeller vanes, within the annular recesses 58 formed in the ends of the drum. This arrangement necessitates offset webs 51, as illustrated in Fig. 4.

Suitable means can be provided for properly lubricating the journals for shaft 22, the journalling of sleeves 5I and 52 upon the blocks 23 and 24, and the journalling of rings 53 and 54 upon the sleeves 5I and 52. In this connection pressure lubricators 59, such as grease cups, are shown in communication with the lubricant ducts 6I, in the blocks 23 and 24, and which communicate with the surfaces in contact between these blocks and' the sleeves 5| and 52. Additional ducts 62 in sleeves 5| and 52, also serve to supply lubricant for the rings 53 and 54.

It will be noted that while the inner surfaces of the housing side walls I3 and I5 are in relatively close juxtaposition with the adjacent end surfaces of the drum, a space or passageway 63 is provided about the major part of the drum periphery, and serves to connect the inflow and outflow passages II and I2. Between the inflow and outflow passages the housing is formed to provide a surface 54, which has a curvature coinciding with the surface of a cylinder, with the center of the cylinder coinciding with the axis of rotation of the drum. The surface 54 is in relatively close juxtaposition with the adjacent peripheral surface of the drum, although a slight clearance is provided, in order to prevent direct frictional contact. Likewise directly opposite the curved surface 54, the inner periphery of the housing is formed to provide the surface 66. This surface is likewise curved to coincide with a cylinder, having its center coincident with the axis of shaft 22. 'I'his surface 65 is so proportioned, that with respect to the impeller its extent is greater than the angular distance between any two adjacent impelier vanes. The impeller vanes are so dimensioned, that with respect to the surface 65, the ends of the vanes are spaced from the surface only by a slight amount of clearance. Likewise with a desirable portioning of parts such as illustrated in Fig. 2, the ends of the impeller vanes clear the edges 61 of the surface 64, by only a slight amount. While making reference to the clearances which it is desirable to establish, it may be again pointed out that the segmental members 48 are so dimensioned, that a slight clearance is established between their outer surfaces, and the inner peripheral inner surface of the drum. Thus even when the rotor assembly is operated at a relatively high speed, the segmental members may freely oscillate without being pressed in a direct frictional engagement with the inner peripheral surface of the drum.

Operation of the pump described above can be outlined as followsz--Sutable driving means, such as an electric motor, is connected to the main shaft 22. Rotation of the impeller I8 directly transmits torque to the drum I1, without lost motion, by virtue of the fact that block 39 is directly fastened to the drum. Assuming that the impeller is rotated in a clockwise direction as viewed in Fig. 2, the impeller vane located in the upper part of this view is projected from the outer periphery of the drum, as it moves into the region of the passageway 63. which the vane isprojected from the outer periphery of the drum is at a maximum, when this vane is rotated through 180, and thereafter the vane is gradually retracted, until returned to its initial position. Eccentricity between the drum and the impeller causes the vanes to assume various angles with respect to radii drawn from the center of the drum. Such angular variations are accommodated by turning of the pivot pins 4I and 49, about their axes. Likewise because of the eccentricity, and because one vane has a fixed drive connection to the drum through block 39, the segmental members 49 oscillate as the assembly rotates, the oscillating movement being through arcs of a circle having a center coincident with the axis of rotation of the drum. It will be evident that cyclic projection of the vanes causes fluid to be propelled through the passage 63, from the inflowi Il to the outward opening I2, and the propelling of the liquidv is accompanied by actual trapping of liquid between succeeding vanes, as each vane passes in juxtaposition to the curved housing surface 66.

A feature which contributes materially to the success of my pump, is the fact that it can be operated at moderately high speeds, as for example in the neighborhood of six or eight hundred revolutions per minute, without undue noise or vibration. This is attributed in part to the fact that the impeller has a positive drive connection to the drum, as described above. such a pOsitive drive connection necessarily calls for slight variations in angular velocities between the impeller and the drum, this of itself causes no mechanical dimculty. If it were attempted to have all of the vanes of the impeller associated with segments capable of having oscillating movement with respect to the drum, in order to enable the drum and impeller to theoretically rotate at the same velocities, the lost motion thus afforded between the impeller and the drum would cause serious difiiculty with the result that The extent to4 the pump would besubject to-severe and destructive vibration. Operation occurs with a minimum amount of frictional loss, and without undue wear upon the parts, because of the manner in which the segmental members l48 are journaled, with the provision of a deflniteclearance between their outer surfaces and the adjacent inner surfaces of the drum. Thus centrifugal force can not press the 'segmental members against adjacent surfaces of the drum, to cause an undue amount of friction with the setting up of corresponding severe strains upon the parts. It has also been found that the pump -is not subject to hydraulic pounding when operated upon liquids. This is attributed in part to the fact that the ends of the impeller vanes pass in relatively close apposition to the edges 61 of the curved surface 64, and to the fact that the surface 64 is so formed that when an impeller vane passes beneath the same there is no trapping of liquid which is placed under hydraulic pressure. In this connection note that while a slot in the periphery of the drum is passing along the surface 64, any liquid which may be carried within the same is not placed under severe pressure, before the slot is again exposed. When operating on liquids, the interior of the drum I1 is usually completely filled. Severe hydraulic pounding within the drum is-prevented by virtue of the fact that the impeller has openings through the same, as illustrated in Fig. l, whereby liquid is free to surge through such openings.

It is evident that my pump has many useful commercial applications. For example, it may be used in place of otherl types of positive displacement pumps, which will not afford the capacity desired, and which may notproperly operate on the liquid material being handled. It can also be used in place of cascade centrifugal pumps, where it is desired to deliver liquids to relatively high pressure heads. My pump is also capable of handling gases together with liquids, and in such connection it is capable of drawing a relatively high vacuum.

I claim:

1. In a device of the character described, a hollow housing having fluid inlet and outlet openings, a drum disposed within the housing and rotatable about a fixed axis, an impeller disposed withinthe drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impellerincluding radially extending vanes having xed angular relationship with respect to each other, said drum having cylindrically shaped peripheral wall portions which are fixed with respect to each other and which are interrupted by spaced slots to accommodate said vanes, one of said vanes having a positive drive connection to the drum, segmental shaped members associated with the remainder of the vanes and with said peripheral wall portions of the drum, said members serving as closures for said slots, and mounting means for said members enabling oscillating movement of the same through arcs of acircle concentric with respect to the axis of the drum. l

2. In a device of the character described, a hollow housing having uid inlet and outlet openings, a drum disposed within the housing and rotatable about a fixed axis,` an impeller disposed within the drum and rotatable about an axis eci centric with respect to the axis of A rotation of the drum, the impeller including radially extending vanes having fixed angular relationship with respect to each other, said drum having cylindrically shaped peripheral wall portions which are fixed with respect to each other and which are interrupted by spaced slots to accommodate said vanes, a slotted pin pivotally connected to the drum adjacent one of said slots, one -of said vanes extending slidably through said pin Whereby a positive drive connection is established between the drum and the impeller, segmental shaped members associated with the remainder of the vanes and with said peripheral wall portions of the drum, slotted pins pivotally carried by said segmental lmembers and through which the remainder of the impeller vanes extend, and mounting means for said segmental members enabling oscillating movement of the same through arcs of .a circle concentric with respect to the axis'of the drum.

3. In adevice of the character described, a hollow housing having iiuid inlet and outlet openings, a drum disposed within the housing and rotatable about a fixed axis, an impeller disposed within the drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impeller including radially extending vanes vhaving fixed angular relationship with respect to each other, said drum having end walls and cylindrically shaped peripheral wall portions which are xed with respect to the end Walls and which are interrupted by spaced slots to accommodate said vanes, segmental.

shaped members disposed within the drum and having slots to accommodatesaid vanes, the outer arcuate surface of eachI segmental member being adjacent the inner surface of the peripheral wall portions of the drum, and means for journalling the segmental members for oscillating movements about the axis of rotation of the drum and for maintaining a fixed clearance between the outer surfaces of said members and the inner peripheral surface of the `drum.

`4. In a. fluid displacement device, a hollow housing having iiuid inlet and outlet openings, a drum disposed within the housing and rotatable about a fixed axis, an impeller disposed within the drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impeller including radially extending vanes having fixed angular relationship with respect to each other, said drum having end walls and cylindrically shaped peripheral wall portions fixed to the side walls', said peripheral wall portions being interrupted by spaced slots to accommodate said vanes, one of said vanes having a positive drive connection to the drum, segmental shaped members disposed within the drum and having slots to accommodate the remainder of said vanes, the outer arcuate surface of each segmental member being adjacent the inner surface of the peripheral wall portions of the drum, and means for journalling the segmental members for oscillating movement about the axis of rotation of the drum and for maintaining a xed clearance between the outer surfaces of said members and the inner peripheral surface of the drum.

.5. In a device of the character described, a hollow housing having fluid inlet and outlet openings, a drum disposed within the housing and rotatable about a xed axis, an impeller disposed within'the drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impeller including radially extending vanes having fixed angular relationship with respect to each other, -said drum including wall portions fixed with respect to the end walls, the peripheral wall portions being slotted to accommodate said vanes, segmental shaped members disposed within the drum and each having' a slot to accommodate an associated impeller vane, the outer arcuate surface of each segmental member being adjacent the inner surface of the peripheral wall portions of the drum, and means for journalling the segmental members for oscillating movements about the axis of rotation of the drum and for maintaining a xed clearance between the outer surfaces of said annular members and the inner peripheral surface of the drum, said last means including a pair of journal rings secured to each segmental member.

6. In a device of the character described, a

hollow housing having fluid inlet and outlet openings, a drum disposed within the housing, said drum including rigid end walls together with cylindrically shaped peripheral wall portions fixed to the end walls, means for journalling the drum'to rotate about a fixed axis, said journal means including a pair of sleeves fixed to end walls of the drum and extending to the interior ofthe drum, an impeller disposed within the drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impeller including radially extending vanes having fixed angular relationship with respect to each other, the peripheral wall portions of the drum being provided with slots to accommodate said vanes, segmental shaped members disposed within the drum and having slots to accommo- 7 date said vanes, the outer arcuate surface of each segmental member being adjacent the inner surface of the peripheral wall portions of the drum, arid means for journalling the segmental mem bers for oscillating movements about the axis of rotation of the drum and for maintaining a fixed clearance between the outer surfaces of said segmental members and the inner peripheral surface of the drum, said last means including a pair of journal rings secured to each segmental member, said rings being journalled upon said sleeves.

7. In a device of the character described, a hollow housing having fluid inlet and outlet openings, a drum disposed within the housing, said drum including end walls together with cylindrically shaped peripheral wall portions fixed with respect to the end walls, means for journailing the end walls of the drum with respect to the housing, whereby the drum is caused to rotate about a fixed axis, an impeller disposed within the drum and rotatable about an axis eccentric with respect to the axis of rotation of the drum, the impeller including radially extending vanes having fixed angular relationship with respect to each other, the peripheral wall portions of the drum being provided with slots to accommodate said vanes, a slotted pin disposed within the drum and through which one of said vanes extends, means forming a fixed pivotal mounting for said pin upon said drum whereby a positive drive connection is established be tween said one vane and the drum, segmental shaped members disposed within the drum and associatedwith the remainder of the vanes, said members having slots to accommodate the remainder of said vanes and the outer arcuate surface of each segmental member being ad ing movements about the axis of rotation of the drum and for maintaining a fixed clearance between the outer surfaces of said members and the inner peripheral'surface of the drum, said last means including a pair of journal rings secured to each of said-segmental members.

HENRY J. GERDAU.

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