US2157089A - Pump - Google Patents

Description

y ,1 H. A. STORCH El AL I 2,157,089

PUMP

Filed Oct. 26, 1955 2 Sheets-Sheet 1 INVENTORS.

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H. A. STORCH ET'AL ,157,089

PUMP

" May 2,1939.

I Filed Oct. 26, 1935 2 Sheets-Sheet 2 1% ENTORS. 5 arc 3?) X 21720. 8Y5 11a)? QZ JW ZZ.

ATTORNEYS- Patented May 2, 1939 UNITED STATES PATENTI' OFFICE Harold A. Storch, Raymond V. Dillon, andistnart H. Caldwell, Detroit, Mich, asslgnors, by mesne assignments, to Chandler-Evans Corporation, Detroit, Mich, a corporation of Michigan Application October 26, 1935; Serial No. 46,856

6 Claims.

While the particular fluid transmission system 10 disclosed herein is illustrated in connection with a fuel supply for airplane engines, it will be appreciated from the following description and accompanying drawings that this system may find marked utility invarious other flelds. As is well known, in fuel feeding systems for airplanes it is quite essential that an even, constant and uniformsupply of fuel be available to the carburetor from the fuel reservoir at all times, irrespective of the relative vertical positions of the tank and carburetor and irrespective of the rateof consumption of the fuel. a

A primary object of the present invention consists in the provision of a pump which has a relief valve associated therewith to by-pass fluid from the discharge side of the pump back into the intake side in order that the discharge pressure willbe maintained at a predetermined maximum.

As is conventional in the art, pumps of this gen eral type are built sufliciently large sothat they will feed an amount of fluid substantially inexcess 01' that required at times of maximum load.

Thus, to prevent an undue building up of pressureon the discharge side of the pump, it is necessary to provide a relief valve which will permit a return of the surplus fluid from the discharge side of thepump back into the intake side of the pump, thus retaining the discharge pressure at all times, at a predetermined maximum. I

It has been found that at various times, unde 40 various load conditions, and various angles at which the fuselage of. the airplane may be inp clined, the suction force required to draw fluid from the reservoir through the pump varies substantially. Consequently, it has been found that the suction pressure on the intake side of the pump and to which one surface of the relief valve is necessarily exposed, varies" substantially and consequently hasa material influence on the action of this relief valve. It is therefore an 5Q object of the present invention to provide meanstype, the relief valve has a marked tendency to flutter and vibrate as a result of minor fluctuations in discharge pressure. This'fluttering and vibration of the valve has been found to cause fatigue and consequent crystallization and break- 5 down of the metallic bellows used on the intake side of the valve to balance the suction'pressure.

It is, therefore, a further object of the present invention to provide means for-dampening the fluctuation and fluttering of this relief valve. The 10 present invention contemplates the utilization of dampening means for this relief valve which will in no way impair the sensitivity of operation thereof or'its response to relatively small fluctuations in discharge pressure. 15

Still further, the invention contemplates a fluid transmission system in whichan auxiliary manually operated pump is connected in serieswith the mechanically operated pump in the fluid transmission line. As long as the mechanically oper- 20 ated pump serves satisfactorily to convey fluid from the reservoir to the carburetor of the enure of the mechanically operated pump, fluid may be forced from the reservoir to the carburetor of the motor by actuation of the hand operated pump and theinvention contemplates the pro- 30 vision .of means in the relief ,valve, which serves to control the discharge pressure of the mechanically operated pump, for permitting the by-pass+ 7 ing. of fluid from the manually operated pump past the mechanically operated pump, directly to 35 the carburetor. 7

It has been found further that the interior construction and configuration of the pump housing and the housing surrounding the by-pass valve have a material bearing on the sensitivity of this 40 valve to the control ofdischarge pressure of the pump. It has been found that the shape and configuration. of the interior fittings of the pump housing with which the 'fluid comes. in contact when circulated through the pump have a, uery 45 definite bearing on the discharge pressure produced in the pump at varying speeds. It is therefore a further object of the present invention to provide a pump construction which has internal parts particularly shaped and adapted to maintain av uniform discharge pressure throughout a relatively wide rang of operation. In furtherance of this general object, the present invention contemplates the provision of a substantially symmetrical. pump housing and the provision of baflie structures within the pump housing which may be cut away in order to calibrate the pump o a particularly desired optimum calibration.

It will be appreciated that it is quite desirable in fluid transmission systems of this general type to maintain as near as possible an exactly uniform discharge pressure from the pump, irrespective of the rate at which the fluid is consumed and irrespective of the elevations of the fluid reservoir and the carburetor or other source to which the fluid is fed. The present invention contemplates the provision of a substantially symmetrical valve mechanism which may be mounted interiorly of the pump housing and which, due to the symmetrical construction of the pump housing, may be changed from end to end in order that the pump maybe driven in either direction as may be desired.

It will be appreciated fromthe foregoing that while the specific embodiment of the invention illustrated in the accompanying drawings and described in the following specification is directed specifically to a fuel feeding system for feeding gasoline to the carburetor of an internal combustion engine in an airplane, this form of the invention is merely illustrative of one of many embodiments of the inventive concept disclosed herein. Many other and further objects, advantages and uses of the inventive concept taught in this application will become apparent to those skilled in the art from a consideration of the accompanying drawings forming a part of this specification.

In the drawings:

Figure 1 is a side elevation of an airplane embodying the novel fluid transmission system.

Figure 2 is a side elevation of the auxiliary pump used in the improved fluid distribution system showing its connection to the fluid reservoir and to the main pump.

Figure 3 is a sectional view taken on the line 33 of Figure 2 and is a transverse sectional view through the mechanically operated pump.

Figure 4 is a sectional view taken on the line 4-4 of Figure 3 and is a longitudinal section through the improved pump and by-pass valve.

Figure 5 is a sectional view taken on the line 5-5 of Figure 4 showing the means by which the by-pass valve mechanism is secured in place.

Figure 6 is a sectional view taken on the line 66 of Figure 4 illustrating the vibration dampener mechanism for controlling vibration and fluttering of the by-pass valve.

With more particular reference to the drawings, the speciflc embodiment of the invention illus trated therein includes a fluid reservoir 1 adapted to be located in the fuselage of'an airplane rearwardly of the cockpit thereof, as is seen in Figure 1 of the drawings. A line of piping 2 connects the fluid reservoir with one side of the mechanically operated pump. at a suitablepoint in the line 2, adjacent the cockpit of the airplane, a-check valve 3 of conventional construction is located in. the lineof piping 2, and is adapted to permit'the flow of fluidin one direction only through the line. On either side of the check valve 3, branch lines 4 and 5 are connected which respectively connect with a manually operated pump 6. The pump 6 may be of conventional construction and in general comprises a cylinder 1 which has a reciprocably operated piston 8 therein actuated by means of a suitable hand lever B. Valves II and Ii are located in the end of the cylinder] and serve to control the passage of fluidto and from the cylinder. It will be apparent that upon actuation of the hand lever 9, which preferably extends upwardly into the cockpit, fluid may be passed through the pump pipe line 2. 7

The primary mechanically operated pump pref erably comprises a housing l5 which is substantially symmetrical longitudinally and is preferably and forced along the formed of a single integral aluminum casting. In

the longitudinal central portion of the housing i5 is locateda cylindrical pump chamber i 6 in which is eccentrically mounted a pump rotor 11. This pump chamber I6 is preferably lined on all sides with wear-resisting material such, for example, as the cast iron sections IS. The pump rotor, as is conventional in the art, has mounted therein a pair of radially reciprocable spring pressed blades which are normally urged radially outwardly into engagement with the liner of the pump chamber by means of a substantially diametrically disposed compression coil spring 20. An intake port 2| and a discharge port 22 are symmetrically disposed on opposite sides of the pump chamber I8 and serve to provide means by which fluids may be taken into the pump chamber and passed therethrough by the pump blades IS. The housing I5 is provided with a threaded aperture 23 adjacent the intake port 2| which is adapted to receive the pipe line 2 from the reservoir I. On the opposite longitudinal side, the housing I5 is provided with an exhaust port 24 which serves to i provide means for connecting a pipe line from the pump to the carburetor or other source of use for the fluid pumped. The pump chamber 16 is closed at one of its axial ends by means of the cover plate 25 threaded into the housing l5. This cover plate 25 serves to provide means for mounting the pump rotor within the pump chamber and also means for assembling the pump rotor elements and liner members of the chamber therein. The rotor of the pump is driven by means of a rotary shaft 26 mounted for rotation in a suit: able bearing 21 and escape of fluid from the pump chamber along the drive 2S is controlled by means of an expansible sealing element designated generally by the reference character 28 which serves to prevent leakage. The construction of this sealing element 28 forms no part of the present invention and is disclosed in detail in Patent No. 1,975,- 352 to Dilg and assigned to the assignee of the present invention.

The pump shaft 26 is universally connected to a suitable operating shaft 30 which may be connected to the motor with which the fuel feeding system is used or any other suitable source of rotational power.

The particular construction of this universal connection between the operating shaft of the pump and the drive shaft thereof is also disclosed in detail in the prior patent referred above.

A substantially cylindrical longitudinally extending valve housing I5 is located in the longitudinal central portion of the housing l5 directly below the pump chamber l8 therein. This valve housing member is preferably formed integrally with the housing i5 and has mounted therein a streamlined valve seat member 35. It is noted that this valve seat member 38 is beveled in order to provide for a relatively smooth flow of fluid through the aperture thereof and is provided with conical annular valve seats on opmany of its axis cooperates with the valve seat 88 in order to provide a clomre for the by-pass valve. The stem 89 of the'valve 88 has at its base portion a disclike member- 88 which serves to provide a closure for one end of a metallic bellows, syphon or other fluid pressure responsive device II. The opposite end of the sylphon 8| is secured to an annular washer 82, the outer periphery of which is adapted to be seated in a suitable shoulder 48 formed in the' wall of the housing l5. This washer 42 is retained in place by means of an annular 'closure member 88 threaded into the wall of the housing; An adjusting screw 88 is threaded into the annular closure member llaxially thereof and has extending axially aplurality of grooves 81 in its outer periphery. A locking member comprising a ball 48. spring pressed by means or a compression coil spring 88 and an adjusting screw il is radially disposed in the annular closure member 88 and serves to engage one of the grooves 41 in the adjusting'screw 88 in order to retain this screw in accurately adjusted position, A compression coil spring 82 has one end by the base of the piston 88.

thereof engaging the set screw. 48. and the opposite end engaging thebase of the valve stem '39 inside of the Bylphon 81.

From' the foregoing it will be apparent that the spring 82 serves to urge the valve 88 into engagement with its seat 88. The pressure by which this valve is urged against its seat is very accurately controlled by means of the adjusting screw 88 and it will be-appreciated that after an adjustment hasonce been made, the adjustment may be permanently maintained by the locking action of the spring pressed ball 88.

The Sylphon ti has a mean diameter substantially identical with the diameter of the valve 38 in order that the eifective area thereof, which willbe subjected to pressure, will be substantially the same as thatof the valve. It is noted that the Sylp 11 8| and the valve 88 are located in an intake chamber 55 which communicates with the intakeside of the pump through a port 58. Consequently, it will be seen that when the pump is run in the direction indicated by, the arrow, a substantial suction pressure will be set up by the pump on the intake side thereof tending to draw fluid into the pump from the reservoir 1 through the pipe line 2. It will be seen that substantially this same suction pressure is transmitted to the valve 88 and would normally tend to raise this valve from its seat were it not for the fact that an equal amount of pressure is exerted on the Sylphon 8| which will tend to expand and balance the pressure exerted on the valve. From the foregoing. it will be clear that any fluctuations oi pressure in the intake side or the pump which would influence operation of the valve will be balanced by the Sylphon 8|. The dischargeside of the pump has a chamber 80 on the opposite side of the valve seat 88 which is substantially identical in 'size' and construction with the chamber 88, just described, and communicates with the discharge side of the pump through a port 8i substantially the same size and construction as the port 58 on theintake side. aperture therein which is adapted to receive and secure a longitudinally extending rod '85 which hasa piston 86 secured to its outer end. The

75 thereinwhich provides a port by which the in- The valve 88 has an axially extending terior oi the cylinder may communicate with the chamber at the discharge side oi the pump. It is noted that the casting 88 and cylinder 8'I extend into the discharge cavity 88 in substantially the same manner as Sylphon H extends into the intake cavity. This construction provides a symmetrical arrangement which, as will be hereinafter serves to provide accurate means for calibrating the pump.

It will be noted that the Sylphonll and the dash pot piston 88 in its cylinder 81 provide the' sole or only supporting and guiding means in the organization for the valve 38 and its stems 89 v and 88.

A plurality of axially extending apertures 18 are provided through the body .of the valve 88. These apertures 18 are normally maintained closed by means of a flexible disc 1| annularly surrounding the rod 88 and retained in position by means of the metallic washer element I2 which is supported in position by means of a compression coil spring 13 having one end abutting thereagainst and the opposite end confined and that due to the fact the piston is connected directly to the valve 38, such fluid must be drawn in or expelled'irom the cylinderas the valve is moved. It will ,further be clear that due to the relatively small size of the port 89, this cylinder and piston will serve as a dashpot and provide eflective means for dampening any fluttering or vibration of the valve 38. The flexible sealing member H, which serves to close the ports 10 through the valve, will normally be inoperative. However, should some failure of the pump occur, it will be possible to set the auxiliary operated pump into operation by manually reciprocating the handle 9. It will be clear that as this handle 9 is reciprocated, fluid will be forced through the line 2 into the intake chamber on the intake side of the pump and'will serve to raise theflexible member H from its seat, consequently permitting the passage of fluid through the port I8 into the dtscharge side of the pump and from thence to the carburetor of the engine or other point of use.

It will appear that the intake and exhaust sides of the housing are substantially identical. It will be noted that when the closure member 48 is unscrewed, it will be possible to withdraw the,v Sylphon device H, the valve 38 connected thereto and also the piston 88, its rod 85 and the complete auxiliary valve assembly ll, I2, .and 18. It may then be appreciated that the cylinder member 68 may be unscrewed from its side of the casing and that the whole valve assembly may then'becompletely reversed with respect to the casing, the only change in structure being that parts are inserted. into positions. substantially as shown and connected up to a source of fluid,

and pressure responsive means are connected to the discharge side of the pump in orderthat the discharge pressure may be accurately measured.

The pump is then run in the direction indicated by the arrow throughout a widely varying range of speed the variations in suction pressure being completely reversed. The pump is then run in the reverse direction and the discharge pressure again calibrated. It will be seen that when this valve mechanism is reversed, the discharge pressure will be determined at the side of the pump which was formerly" the intake side thereof. The

'wall of the valve seat housing which-serves to define a portion of the port 56 is then cut away until a uniform discharge pressure is maintained an at all speeds of the pump.

It is noted that this method of calibrating the pump is made possible by the fact that the pump housing, the valve seat construction and the various ports thereof are substantially symmetrical in construction. Consequently, it is possible to place the valve mechanism in either of one of two positions and reverse the valve mechanism as may be desired. It has been found that the cutting away of this valve seat housing member to enlarge the ports to a predetermined size has proven a very effective and accurate means of calibrating the pump. From the foregoing, it will be appreciated that a novel and distinctive pump construction has been created which is provided with means for maintaining an accurate, substantially uniform discharge pressure throughout a widely ranging change of conditions to which the pump may be subjected during its use. It is further noted that the by-pass valve mechanism described above provides means by which fluid may be forced through the pump mechanism from an auxiliary pump in case of failure of the primary pump to operate. Means have been provided for preventing flut- 5 tering of the valve and the consequent destructive action on the metallic bellows which functions to balance the suction thereby materially increasing the life of this member. It will be further appreciated that a construction has been provided in which such dampening is possible without in any way affecting the sensitivity of the by-pass valve to minor fluctuations in pressure. Still further, it will be appreciated that a .by-pass valve construction has been provided in which widely varying suction pressures on the intake side of the valve will have no tendency to cause an opening of the by-pass valve.

It will be understood that the invention disclosed in the drawings and described in the fore- 00 going specification is merely illustrative of a specific form of the generic concept defined in the sub-joined claims. Many other and further objects and advantages will be apparent to those skilled in the art.

35 What is claimed is:

1. A by-pass valve construction for use in connection with a fluid pump, including a housing having inlet and outlet chambers therein, said housing being formed to provide inlet and outlet 70 ports respectively communicating with said inlet and outlet chambers, a valve seat having an opening therein serving to provide communication between said chambers, a disk valve adapted to cooperate with' said seat to close said opening,

76 said valve having a stem projecting into each of said chambers, an expansible bellows connected to said valve stem and disposed in one of said chambers .andone element'of a dash pot connected to said valve stem in the other of said.

chambers, an aperture through said valve, an auxiliary valve means for closing said aperture and resilient means confined between said dash pot element and said auxiliary valve means for seating the same in position to close the aperture through said disk valve.

2. A by-pass valve construction for use in connection with fluid pump, including a housing having inlet and outlet chambers therein, said housing being formed to provide inlet and outlet ports respectively communicating with said inlet and outlet chambers, a valve seat having an opening therein serving to provide communication between said chambers, a valve adapted to cooperate with said seat to close said opening, said valve having a stem projecting therefrom into one of said chambers, a cylinder in said chamber, a piston within said cylinder, said pistonbeing secured to said valve stem thus providing a dash pot to dampen the action of said valve, said valve having an aperture therethrough, valve means for closing said aperture, and a spring confined between said dash pot piston and valve means for retaining the latter seated in position to close said aperture.

3. A by-pass valve construction for use in connection with a fluid pump, including a housing having inlet and. outlet chambers therein, said housing being formed to provide inlet and outlet ports respectively communicating with said inlet and outlet chambers, a valve seat having an opening therein serving to provide communication between said'chambers, a disk valve adapted to cooperate with said seat to close said opening;

' said valve having a stem extending into each of said chambers, pressure responsive means to balance the inlet suction secured to one of said stems, said disk valve having an annular series of apertures therethrough surrounding said stem, an annular auxiliary valve member having an aperture therein adapted to receive the other of said valve stems and slidably mounted thereon to close said annular series of apertures, and spring means serving to urge said auxiliary valve member to closed position.

4. A reversible fluid pump by-pass construction including, in combination, an elongated housing having an opening at each end and an intermediate open partition to divide it into inlet and outlet chambers, said partition having a valve seat on each side thereof and said housing being symmetrical end for end, a removably secured closure means for each end, a removable and 'reversible valve assembly including a disk valve member mounted to cooperate with one of said valve seats, pressure responsive means to balance the inlet suction secured on one side of saidvalve member and one element of a dash pot secured on the other side of said valve member, and a second removably secured dash pot element cooperating with said first dash pot element and adapted to be mounted in either end of said housmg. 5. A fluid pump by-pass'valve construction including, in combination, an elongated cylindrical housing having an open valve seat intermediate its length dividing it into inlet and outlet chambers, a disk valve to cooperate with said valve seat and having an axially-extending stem pro- J'ecting from each side thereof into each chamber, a pressure responsive inlet suction balancing awaoea Sylphon mounted in the in end of said inlet chamber and having its free end secured to one end of said stem, a dash pot piston secured to the other end of said stem and positioned in a cooperating dash pot cylinder mounted in the far 4 end of the outlet chamber, the construction being so formed and arranged that said disk valve and its stem are supported and guided solely by the said Sylphon and the said dash pot.

6. A reversible fluid pump by-passconstruction including, in combination, an elongated cylindrical housing having an opening at each end and an open partition at its middle to divide it into symmetrical and similar inlet and outlet chambers, said partition having a valve seat on each side thereof and said housing being symmetrical end for end, a removably secured closure means and its other end secured by one of said end' closure means, and a dash pot piston secured on the other side of said disk valve and the cooperating dash pot cylinder to hold said piston removably secured by the other end closure means, 7

said construction being so formed and arranged that the said Sylphon and the said dash pot are the only supporting or gui means for said disk valve.

:13 A. STOR'CH. RAYMOND V. DILLON.

for each end, a removable and reversible valve as

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