US1867585A - Vacuum pump - Google Patents

Description

July 1,9, 1932. T F MOORE 1,867,585

VACUUM PUMP T. F. MOORE July 19, 1932.

VACUUM PUMP Filed Feb. 16, 1931 2 Sheets-Sheet /nvENToR r f er /YAoxn/Evs 'In/rNE ss Patented July 19, 1932 UNTED SFTES THOMAS F. MOOR-E, OF MOR-RIS PLAINS, NEW JERSEY VACUUM PUMP Application filed February 16, 1931. Serial No. 516,057.

rlhis invention relates to a vacuum Ypump adapted to be used more particularly for withdrawing air from centrifugal hydraulic pumps or from the standpipes used in connection therewith, set forth in myv pending application, Serial No. 380,223, filed July 22, 1929, to reduce the liability of the centrifugal pump becoming airbound, but obviously the same vacuum pump may be used in many e other relations.

The vacuum pump is adapted to be mounted upon or in close proximity to the supporting base for the centrifugal pump in such manner that one and the same shaft may be used as the primary driving means for the impeller and for the piston of the vacuum pump whereby both pumps may be readily transported as a unit from place to place for use more particularly for withdrawing zo Water from the soil preparatory to excavations for superstructures.

`The main object, therefore, of the present invention is to provide a simple, compact and highly efficient vacuum pump which may be easily and quickly applied to the shaft of a centrifugal pump or to an extension thereof so that the two pumps may lie in contiguous relation, thus permitting both pumps to be operated by one and the same power unit so when desired, such, for example, as an electric motor.

Another object is to drive the piston of the vacuum pump through the medium of a power multiplying and speed reducing gear train and incidentally to conserve the power required for operating the vacuum pump and at the same time adapt the speed of operation thereof to the requirements of the centrifugal pump.

Another object is to arrange the gears of the train with their axes in one and the same plane and to divide the gear case along the same plane so that one section thereof may be readily removed for repairs or replacements of the gears as may be required to vary the speed of operation on the vacuum pump to suit the requirements ofthe centrifugal pump with which it is associated.

A further object is to mount the low-speed gear of the train upon a crank shaft having eti) its axis intersecting the axis of the piston cylinder and to connect said low-speed shaft to the piston through the medium of a pitman to produce what may be termed a straight-line action of the driving means for l the piston. f I

Another object is to make the cylinder for the piston separate from the gear case and to provide releasable means for securing those parts together end to end so as to permit @o either part to be removed independently of the other part for repairs or replacements when desired.

Another object is to provide the cylinder with a system of air passages through which the air is circulated by the action of the piston and also to provide a system of valves controlled by the circulation of air for controlling the air intake and air exhaust to and 1 from the pistonchamber of the cylinder. 79

Other objects and uses relating to specific parts of the vacuum pump will be brought'out in the following description.

In the drawings p Figure l is a longitudinal vertical sec- I5 tional view of a-vacuum pump embodying the various features of my invention.

Figures 2 and 3 are sectional views taken respectively -in the planes of lines 2 2 and 3 3, Figure 1.

As illustrated this vacuumpump is rigidly mounted in a'substantially horizontal position upon a suitable supporting, frame A and comprises a gear-case section 1 and a cylinder section 2 secured together end 85 to end byreleasable means, as bolts 3 for rigidly holdin the sections in fixed-relation, the frame being located as nearly as possibl-e at or directly under the center of gravity ofthe pump for balancing the 90 same and reducing to a minimum the vibration incidental to the operation of. the moving parts thereof.

The endrof the gear-case 1 adjacent the cylinder section 2 is provided with 95 an opening 4 which is normally closed by a transverse partition 5 forming the adjacent end of the cylinder section and having a central gland 6 for receiving the piston-rod of the pump, presently described, to

said gear-case being adapted to receive and retain a quantity of oil for lubricating the gears and other moving parts therein.

The cylinder section -2- is provided with a piston chamber -7 having a circular peripheral wall -8 and outer and inner walls -9- and -10-, the latter being arranged in axially spaced relation a distance corresponding approximately to the stroke of the piston.

The end wall -10- ofthe piston chamber is arranged in spaced relation to the transverse partition -5- to form an intervening space and is provided with a gland -11- co-axial with the cylinder for receiving and guiding the piston rod.

A piston 12- is reciprocallyv movable endwise within the piston chamber -7- and is provided with a piston rod 13- extending through the glands -11- and -6- into the interior of the gear case section -1-, the inner end of said rod being secured to a cross-head 14- which, in turn, is movable along and upon suitable guideways 15- as shown more clearly in Figure l.

These guideways are rigidly secured to and are preferably formed integral with the transverse partition -5- to extend therefrom into the gear case w-1- a distance corresponding approximately to the stroke of the piston for guiding the cross-head and piston in their rectilinear movements.

The inner end of the piston rod -13- is threaded and engaged in a threaded aperture in the adj acent end of the cross-head -14- and is also engaged by a lock nut l5- for holding the cross-head and piston rod against accident-al displacement one from the other.

rlhe guideways l5- form a part of the cylinder section -2- but are located within the gear-case so that they, together with the cross head 14- and pit-man connection therewith, may be lubricated by the oil-splash from the gears and other moving parts of the piston-actuating means.

The other end of the cross-head lllis provided with a central chamber -16- for receiving the adjacent end of a pitman #17- and a transverse pivotal pin -18- by which the pitman is pivotallfy connected to the cross-head with its axis intersecting the axis of the rod as shown in Figure 1. Y

The other end of the pitman -17-' is ournaled upon a wrist pin -19- forming a part of a crank shaft -20-v which in turn is journaled in the opposite upright side walls of the gear case 1- to rotate about an axis intersecting the axis of the piston chamber -7- and piston rod -13, said wrist pin being counterbalanced by a weight -21- forming a part of the crank arm as QOL- of the crank shaft, it being understood that the crank shaft 20- is arranged some distance from the inner end of the guideways -15- at right angles to the axis of the piston rod -13- and parallel with the connecting pin *18- between the pitman 17- and cross-head J4- A primary drive shaft -22- is journaled in suitable bearings in one or both sides of the gear case l-- in a plane some distance above the guideways -15- and also some distance from the crank shaft -20-.

The drive shaft -22- may be an extension of, or co-axial with, the impeller shaft of a centrifugal pump, not shown, so that both shafts may be operated simultaneously at the same rate of speed by a single power unit, such, for example, as an electric motor.

Suitable means is provided for transmitting rotary motion from the drive shaft 22- to the crank shaft -20-, said means consisting, in this instance, of a speed reducing and power increasing gear train comprising a drivingpinion -23- tight on the drive shaft and meshing with an intermediate gear 24- which is secured to a co-axial pinion -25- so that both may rotate upon a supporting stud or shaft -26-, the pinion -25- meshing with a relatively larger gear -27- which is secured to the crank shaft -20-.

The axes of the shafts -20-, -26- and -22- are disposed in one and the same plane diagonal to the axis of the cylinder or, at an acute angle to said axis as shown in Figure 1.

The gear case -1- is divided in about the same plane as the axes of the shafts -20-, 26 and *22- and therefore diagonal to the axis of the cylinder to form lower and upper sections -28- and -29-- The upper section -29- is removable and constitutes what may be termed a cap section to permit access to the interior mechanism and particularly to allow the gears to be removed or replaced for repairs or for changing the speed ratio of the gear train between the driving shaft 22- and crank shaft 20- as maybe desired to adapt the vacuum pump to varying sizes or capacities of the centrifugal pump with which the vacuum pump is associated, it being understood that portions of the bearings for the shafts Q2- -26- and -20- will be formed in the meeting edges of the gear case sections Q8- and Q9-, which latter may be secured by any suitable releasing means, such as bolts, to the adjacent portions ofthe lower secti on -28* to form a liquid tight joint therein so that the entire gear case may receive and retain a sufficient quantity of oil for lubricating the various moving parts therein and thereby to reduce the noise incidental to the operation of those parts.

Y Air circulation control The cylinder section -2- is provided with separate diametrically opposite air chambers -30- and -;3larranged respectively above and below the piston chamber -7-, the central outer portion of the chamber being cylindrical and reduced in diameter and connected by a pipe 32- to the interior of a centrifugal pump or standpipe leading thereto, not shown, or to any other apparatus from which air is to be withdrawn.

The chamber -80- constitutes what may be termed the air intake chamber and therefore the conduit -32 leading thereto may `be termed the air intake pipe or conduit which is arranged substantially midway between opposite ends .of the piston chamber 7 and extends axially some distance beyond opposite sides of the intake conduit 32- as shown in Figure l.

The upper portion of the cylinder section -2 is provided with a'pair of valve chambers -33- and -33- located at opposite sides of the intake conduit -32-, the valve chamber -38 being connected by a passage .34- to the adjacent end of the upper portion of the piston chamber 7* and is -also connected by Aa port *B5- to the adj a- -cent end of 'the airiintake chamber -30-.

The other valve chamber -33- is connected by apassage -34lto the upper portion of the corresponding end of the piston lchamber -7- and is also connected by a port -35- to the adjacent end of the air intake chamber -30-. Y

These ports --and -35- are respectively controlled by ball valves @5* and -Z)-, normaly seated in the upper portions thereof by their ownweig'ht and'therefore are `self-closing but adapted to be openedv by the circulation of kair caused by the movements of the piston -12- in a manner presently described.

These valves also control communication between the Vair intake chamber 30- and passages 84- and -34- respectively through the medium of the ports 35- and -35- and are held against undue upward displacement by cap portions -36 and -36-- which are releasably secured in openings in upper portions of the valve chambers -83- and -33- to permit access to the valves for repair or replacements when desired.

The lower wall of the lower air chamber 3lis provided with a reduced cylindrical opening connected by a pipe or conduit -37- to the external atmosphere or to any other suitable place of exhaust. The chamber -3l constitutes what may be termed the exhaust chamber and extends axially some distance beyond the opposite sides of the exhaust pipe -37-, the opposite ends of said chamber being respectively connected by ports -38- and -38- to separate exhaust passages -39- and -39- which in turn are connected to corresponding ends of the .lower portionof the piston chamber -7-as lshown Vin Figure 1.

The lower walls of the exhaust passages I 39 and -39- are provided with cleanout 'spaced from the bottom 'walls of the chambers a distance somewhat less than the diameters of the valves to enable the liquid to pass freely from the ports -38- and -SSQ to the outlet conduit -37 as Vshown in Fig ures l and 2.

One of the upright side walls of each of the valve chambers -40- and l0 is provided with an opening -l3 of size to .permit the insertion and removal. of their respectiveV valves cfand therethrough, said openings being normally closed by 'a cover plate 114- which is releasably secured to the valve case by bolts 4:5* or equivalent fastening means, Figures l2 and 3.

Operation, n Assuming now that the gear train is in operation and that the piston has just been forced to its extreme outer position as shown 1n Figure l, then as the piston-1s moved 1n- `wardly the ball valve -awill be opened by reason of the partial vacuum formed in the passage 34.- and higher air pressure in the chamber -30, thus permitting the inflow of air from the conduit -32- through the port 35- and passage S4- into the outer end of the piston chamber, while at the same time the exhaust valve -b will remain closed by reason of the partial vacuum created in the passage 39? and higher air pressure in the exhaust chamber -31-.

During this inward stroke of the piston, the valve -awill be opened bythe comvpressedair inthe passage -39- by reason of the lower air pressure inV the exhaust Ychamber -3l-, therebyallowing the air to `escape from the piston chamber vthrough the passage -39- and open port 38'- and thence out through the exhaust conduit m37-, while at the same time the air compressed by the inward movement of the piston in the passage -84 will cause the valve -b to remain closed by reason of the lower pressure in the intake chamber -30-.

The inlow of vair into the outer end of ,the

vpiston chamber and outflow of air from the inner end of said chamber will continue during the entire inner stroke of the piston.

On the other hand, during the out-stroke of the piston, the valve -bwill be opened to allow the air from the corresponding end of the piston chamber to flow outwardly through the exhaust conduit -37- and the Aopposite valve ur/ will remain closed while the valve will also be opened to allow air to enter the inner end of the piston chamber through the passage 3ythis latter condition existing during the entire out stroke of the piston.

Brieiiy stated, during the instroke of the piston the intake controlling valve a and exhaust controlling valve -awill both be opened while the other valves Z5-- and will be closed, but during the outstroke of the piston the intake valves and exhaust valves -ZJ- will be opened and the other valves -aand -awill be closed so that a substantially continuous stream of air will be drawn into opposite ends of the cylinder during the reverse strokes of the piston and at the same time the air drawn into the cylinder will be continuously exhausted therefrom through the exhaust pipe -37 thus constituting what may be termed a double acting vacuum pump.

During this reciprocal movement of the piston -l2- by means ot the gears -23-, -24-, Q5- and -26-- and the pitman -17- the balanced condition of the pump on its supporting frame reduces the vibration of said pump to a minimum and thereby assures accuracy of operation of the valves and at the same time the action of the gears, crankshaft and pitman within the oil containing case and resultant splashing of the oil serves to automatically lubricate all of the moving parts within said case, including the gland -6-.

It will be noted that by arranging the valve case in a vertical position, all ot the ball-valves are self-closing by their own weight and that they are automatically opened in sequence in the order described by the varying air pressures above and below the same produced by the action of the piston.

element and a cylinder element releasably secured together end to end, a partition extending transversely across the meeting ends of said elements and provided with a gland co-axial with the cylinder element, a piston reciprocally movable endwise in the cylinder element and provided with a rod extended through said gland, power-oriven means including a gear train in the gear-case element operatively connected t0 said rod for reciprocating the piston, said cylinder being provided with air inlet and outlet passages and valves controlled by the movement of the piston for controlling said passages.

2. A vacuum pump comprising agear-case, a cylinder having air inlet and outlet passages, releasable means for securing said gear-case and cylinder together end to end, a partition extending transversely across the meeting ends of the gear-case and cylinder and provided with a guide-way extending into the gear-case, a cross-head reciprocally movable alongv said guideway, a piston in the cylinder operatively connected to the crosshead to receive motion therefrom for circulating air through the inlet and outlet passages, and means including a train of gears in the gear-case for operating the cross-head.

3. A vacuum pump comprising a gearcase and a cylinder secured together end to end, said cylinder having air inlet and outlet passages, a piston reciprocally movable endwise in the cylinder for circulating air through said passages, valves controlled by the circulation of air for controlling the passages,-and power-driven means including a train of gears within the gear-case for reciprocating the piston, said gears having their axes disposed in one and the same plane, the

gear-case being divided alongsaid plane into opposed sections, one of which is removable. In witnesswhereof I have hereunto set my hand this 13th day of February, 1931.

THOMAS F. MOORE.

Furthermore, by making the gear-case with Y the gears and pitman therein as one unit and the cylinder and valve-case with the piston and valves therein as a separate unit in the manner shown and described, either unit may be detached from the other unit without disturbing the contained parts mentioned by simply removing the bolts -3- and disconnecting the pivotal pin -18-, the latter being accessible when the lid -29- is removed, vunder which conditions the cross-head 14- and its guideways -15- would be removed with the case section -2-. See Figure l.

l. A vacuum pump comprising a gear-case

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