Патент USA US2105999код для вставки
2,105,999 Patented Jan. 18, 1938 UNITED srATEs2,105,999PATENT OFFICE PUMP STRUCTURE James Moore Evans, Detroit, Mich, assignor, by mesne assignments, to Grade Crossing Guard Corporation, Memphis, Tenn., a corporation of Tennessee Application August 2, 1935, Serial No. 34,323 2 Claims. (01. 103-41) The present invention relates to pumping mechanism, and more particularly to pumping mechanism‘ constructed to provide a positive ?ow in one direction, and to permit a relatively free flow in an opposite direction. It is an object of the present invention to provide a pump constructed to provide a positive ?uid ?ow in one direction, and to permit a rela tively free ?uid flow in an opposite direction. It is also an object of the present invention 10 to provide apump structure embodying a pump chamber and selectively controllable means to permit a relatively free flow of ?uid around the‘ pump chamber. \ tively draw ?uid from the inlet chamber and discharge it through the outlet chamber. In order to permit a relatively free ?ow of ?uid through the pump structure without passing through the pump chamber, selectively controlled valve mechanism is provided to complete an aux iliary* connection between the inlet and outlet chambers. 'As illustrated, the inlet and outlet chambers are provided with a common separating wall, and‘ the valve mechanism is positioned to open and close a port provided in such common separating wall. 0 . The arrangement is preferably such that the selectively controlled valve responds to the speed of operation of the pump, being moved to a closed‘ 6 position when the pump is operating at or above a predetermined rate, and being moved to an chamber and automatically controlled mecha ‘nism to permit a relatively free ?ow of ?uid ' open position when the speed of operation is It is also an object of the present invention v15 to provide a pump structure embodying a p11‘ 1p around the pump chamber. ' It is also an object of the present invention to provide a pump of the last mentioned char acter in which the by-pass mechanism is re sponsive to the speed of operation of the pump. [It is also an object of the present invention to provide a pump structure embodying a pump ' ing chamber, inlet and outlet chambers, and a selectively controlled valve to control a by-pass port between the inlet and outlet chambers. It is also an object of the present invention 8 to provide a pump- structure embodying a pump , . ‘ In accordance with the present invention’ also, the selectively controlled valve may be rendered independent of the pressures within the inlet and the outlet chambers. As illustrated, this rela 5 tionship is accomplished by arranging the struc ture so that in any position of the valve, the parts directly associated therewith are subjected to equal and opposite components of the pres eration of pump structures. may be accomplished in various ways. As illus Other objects and advantages of the present invention appear in the following description and in the appended claims. valve is mounted for reciprocatory motion in an 0. trated, a piston member rigidly connected to the auxiliary cylinder formed in the pump structure. The cylinder area on one side of the piston com tion; municates with one chamber, and the cylinder area on the other side of the piston communicates with the other chamber. The area presented by the piston is equal to the area presented by the valve when in closed position. In any position of the valve, accordingly, the pressure in either the line 2——2 of Fig. 1; and chamber. exerts equal and opposite forces on the ing numerals are used to designate corresponding parts, Figure 1 is a view in vertical, axial section in an illustrative embodiment of the present inven Fig. 2 is a view in vertical section taken along Fig. 3 is a view taken along the line 3-3 of 50 drives the pump. 0 chamber, and embodying valve mechanism dis posed‘in balanced relation to the pump pressures sures within the inlet and outlet chambers, re to permit a ?ow through the pump independently ’ spectively.‘ With this arrangement, the valve is balanced in any given position with respect to of the pump chamber. It is also an object of the present invention the inlet and outlet chamber pressures. The balancing of the selectively controlled valve, to generally improve the construction and op In the drawing, throughout which correspond- . 4 below such predetermined value. As. illustrated, the speed responsive control of the‘ selectively controlled valve is eiiected by governor mecha nism suitably driven by the mechanism which respectivev valve faces. The present invention also comprises an ar . In accordance with the-illustrated embodiment rangement for ‘providing forpressure relief with of the present invention, the pump ‘structure in the pump structure. As illustrated,‘ a spring comprises generally a pump chamber, an inlet _ pressed check valve is disposed to control a sec Fig. 1. chamber, and an outlet chamber. The pump 55 chamber comprises rotating mechanism to posi ond port in the above mentioned connecting wall. As described more in detail hereinafter, the check: 0 hi 5 2 2,105,999 valve remains closed as long as the pressure with in the_ outlet chamber is below a predetermined value, and moves to an open position when they pressure in such chamber reaches or exceeds such predetermined value. The predetermined value is conveniently adjustable. 64 by a pin ‘I6. Spring 18 is disposed to bias valve 58 to the right, as viewed in Fig. 1, to close open ing 52. As_ long, however, as the speed of shaft 20, and. hence of the pump, is below a certain' value, the centrifugal governor mechanism desig nated generally 80, forces spring 10 to the left, in Considering the above elements in more detail, - which position it actuates valve 58 to the open and referring to Figures 1, 2 and 3, casing I0 is formed to provide a pump chamber‘ 12, an inlet 10 chamber I 4, and an outlet chamber I6. A pump rotor l8, eccentrically mounted in chamber l2 on a drive shaft 20,v and having a ~plurality of pumping blades 22 pressed outwardly by a spring 24, draws ?uid from inlet chamber» l4 through 15 port 26, and forces it into outlet chamber l6 by way of port 28. Chamber l4 communicates with a suitable source of ?uid supply through opening 30, and chamber I 6 is provided with a suitable outlet passage 32. Shaft 20, which may be driven in any suitable manner, is provided with a recessed section 2| over which rotor I8 is ?tted. Spring 23 and plate 25 provide a somewhat resilient thrust bearing for the end of shaft 28. ' Pumping blades 22 are slidably ?tted in dia metrically opposed recesses 21 formed in rotor l8. Spring 24, which biased blades 22 outwardly into engagement with the walls of chamber l2, passes through openings formed in rotor l8 and shaft 28. 30 The common wall 34 which separates chambers l4 and I6 is provided with an opening 36, which is normally closed by a spring pressed release valve designated generally 38. Valve 38 comprises a head 40, slidably ?tted in a recess 42 formed in casing ID; a shank 44 slidably ?tted in a sleeve 46 which is threaded into casing in and termi nates in an external head 48; and a biasing spring 50 which surrounds shank 44 and bears against a shoulder formed thereon and a similar shoulder 40 formed on sleeve 46. Rotation of head 48 inone position. When the pump speed exceeds the pre determined value, however, governor mechanism 80 is retired, and spring 18 is rendered effective 10 to close valve 58. As will be understood, the above mentioned balanced condition of valve 58 permits the use of a relatively light and simple actuating member, and the above mentioned pres sure differential which exists when the valve is 15 closed, aids spring 18 in maintaining the valve in the closed position. ' Although governor mechanism 80 may be of any conventional type arranged to function as above described, it preferably comprises the sleeve 20 14, tightly ?tted on shaft 28; an auxiliary sleeve 84 slidably ?tted on sleeve 14 and having project~ ing shoulders disposed for engagement by the end sections 82 of the two governor arms 86; a pair of weights 88 connected to‘ arms 86 and slidably 25 positioned within a frame 98 which‘ serves to guide the movements thereof and is tightly ?tted on sleeve 14; and a pair of biasing springs 92, disposed to engage pins 94 which pass-through weights 88, and serve to bias the latter inward 30 ly. _As will be understood, upon rotation of shaft 28, governor 88 rotates correspondingly, and weights 88 are centrifugally forced outwardly within frame 90. ,This motion of weights 88 causes arms 86 to move‘ sleeve 84 to the right as 35 viewed in Fig. 1. In response to this spring 10 moves to the right, closing valve 58 and moving ' collar 96 to the right. If the speed of shaft 20 falls below a predetermined value, springs 82 force weights 88 inwardly, causing collar 96 to 40 direction or the othercauses sleeve 46 to move . move to the left. inwardly or outwar‘dly with respect to casing l0, elongating ‘or compressing spring'50 and corre spondingly varying the contact pressure of valve 45 head 40. As will be understood, if the pressure in chamber I6 exceeds the force exerted by spring 50, valve 38 is forced open, permitting the fluid to pass freely between chambers I4 and I6, through ' opening 36, without passing through pump cham 50 ber l2. Wall 34 is also provided with a second opening 52, which affords communication between cham bers l4 and IS. A valve 58, disposed to engage the margins of opening 52 to close the latter, is This action force's spring 10 to the left, re-opening valve 58. / With reference to the operation of the pump as a unit, it will be understood that opening 88 com municates with a. suitable source of ?uid supply, and that opening 32 communicates with a suit able discharge line. With pump rotor 58 at rest, valve 58 occupies the open position as previ ously described. Under these conditions, ?uid is enabled to pass through the pump casing, by way of opening 52, without passing through pump chamber l2. This ?ow may be in either direc-' tion through the pump. " In application of the pump to reciprocatory systems, such for example 55 connected to a piston 68 by a central post 62. as disclosed in the co-pending application of the Piston 60 is slidably ?tted in a cylinder 54 formed ' present applicant, Serial No. 34,322, ?led August on the interior of casing l0, axially concentric with opening 52. A passage 56 connects chamber 2, 1935, and assignedto the same assignee as the present application, in which a corresponding I 6 and cylinder 54. The diameters of piston 68, is utilized to actuate a hydraulic ram, the to cylinder 54 and opening 52 vare the same, but it is pump ?ow of the ?uicl'is ordinarily in a direction op noted that valve 58 is somewhat larger than the posite to that produced when the pump is in oper opening 52. When the valve 58 is closed accord ation. In such instances, opening 52 permits a ingly a, predetermined pressure differential exists return movementhf the ?uid. which urges it to the closed position. When the If the pump is placed in operation, the rotation 65 valve 58 is open on the other hand the pressures of rotor l8 and of blades 22 positively draws ?uid on opposite sides thereof are substantially equal, from inletchamber l4 through pump chamber and differ only by an amount which is caused by l2 into outlet chamber I 6. As long as the speed the cross sectional area of rod 64. of the pump remains below the previously men The shank 64 of valve 58 extends through cas tioned predetermined value, valve 58 remains 70 ing Ill and into the interior of a governor hous open the ?uid thus circulated passes be-. 70 ing 66, which is suitably secured to, casing ill by tweenso'that chambers l4 and I 6 by way of opening 52, studs 68. A spring 18, suitably secured to the and substantially no pressure is developed by the interior of housing 66 by studs 12, surrounds a pump in either of the lines connected to inlet and governor sleeve 14 which is tightly ?tted on shaft outlet openings 20 and 32. As will be understood, 20, and is connected at its upper end to shank valve 58 may be caused to close at any desired 75 3. ' 2,105,999 operating speed of the pump. The preferred operating speed is approximately one-half of the normal full operating speed'of the pump. Upon closure of valve 58, the inlet and outlet chambers l4 and ii are isolated from each other except through pump chamber l2. Accordingly, ' the ?uid circulated through the pump is drawn from the inlet passage and passes out through the outlet passage, the pressure developed being determined by the pump characteristics. If the speed of the pump falls below the pre determined value, governor mechanism 80 actu ates valve 58 to the open position, permitting the previously -mentioned circulation of the ?uid 15 within the pump. Upon the opening of valve 58, the pressure developed by the pump in the line connected to passages 30 and 32 falls to substan tially zero. If the ?uid in these lines is subjected to any reverse pressure, such reverse pressure re sults in a, reverse flow of the ?uid through the pump by way of opening 52. If at any time during the operation of the pump, the pressure within outlet chamber l6 ex ceeds a predetermined value, relief valve 38 is 25 actuated to the open position, connecting inlet and outlet chambers l4 and I6 respectively by way of openings 36, again permitting a circula tion of the ?uid within the pump. ’ Although a speci?c embodiment of the present invention has been described,'it will be evident that various modi?cations may be made in the form, number and arrangement of parts with out departing from the spirit or scope thereof. The described embodiments, accordingly, are to to de?ne separate inlet and outlet chambers dis posed on opposite sides of the interior wall, a rotary impeller in said casing for transmitting ?uid between said inlet and outlet chambers, said impeller being provided with a shaft pro jecting outwardly of said casing, said interior. wall having an opening therein to form a by; pass connection between said chambers, a valve movably supported in said casing for opening and closing said opening and having an operating 10 rod projecting outwardly of said casing, and a speed responsive means on said shaft having an > operating connection between the shaft and the rod externally of the casing whereby said valve will be closed upon attainment of predetermined 15 speed. _ r 2. In a pumping mechanism, a casing provided with outer enclosing walls and an interior wall to de?ne separate inlet and outlet chambers disposed on opposite sides of the interior wall, a rotary impeller in said casing for transmitting ?uid between said inlet and outlet chambers, said impeller being provided with a shaft pro jecting outwardly of said casing, said interior wall having an opening therein to form a by 25 pass connection between said chambers, alvalve movably supported in said casing for opening and closing said opening and having an oper ating rod projecting outwardly of said casing, means associated with said valve for subjecting 30 it when closed to a ?uid pressure differential acting in a direction to hold it closed, and a speed responsive means on said shaft‘ having an operating connection between the shaft and the rod externally of the casing whereby said valve 35 be considered in- an illustrative and not in a -' will be closed upon attainment of'predetermined limiting sense. What is claimed is: ' 1. In a pumping mechanism, a casing provided with outer enclosing walls and an interior wall speed. ‘ JAMES MOORE EVANS.