US2336996A - Hydraulic generator - Google Patents

Description

Dec. 14, 1943- E. w. McDoNouGH HYDRAUL I C GENERATOR Filed Nov. 27, 1940 2 Sheets-Sheet 2 I .'PatentedfDec. 14, 1943 PATENT OFFICE HYDRAULIC GENERATOR Edward W. McDonough, Chicago, Ill., assigner to Aircraft Specialties, Chicago, Ill.

:Application November 27, 1940, Serial No. 367,332

5 Claims.

This .inventionrelates to hydraulic pumps and `in particular.VA to the .rotatingtype of pump for producing very highpressures.

'.'I'he device of thisinvention .is a rotary hydraulicV generator of ktherpiston type which is capable of pumping iluid into a system and maintaining it in the systemxat very. high pressures of the order of three thousand pounds per square inch.

-Becauseof thatfeaturel and because of the 1 multiplicity of varied things to be done in the operation of aircraft) requiring vanv immediate -source of powerfthe .device of this invention is particularly adaptedfor use on airplanes. However, the use of the pump ofthis invention is 20 in no `way-restricted to use .on airplanes but may be used to very'fgreat advantage wherever it is desirable to maintaina live line of power which may be utilized at any instant to perform work.

There aremany objects and features of this invention, some .of which are inherent to the structure -of thedevice, and all of :which can be better understood and. appreciated from a description ofthe apparatus ofthis invention in Iconnection with the` accompanying drawings. In

addition to thetWo-sectionalviews of the pump proper, 'Figures/land?, several other illustrations of important elements of the live line hydraulic generator of this invention have been shown 4in detail so as .to supplement the two `principaliviews and completely disclose to those in this art the construction and features of the hydraulicgenerator of this invention.

i Figure, 1 is a sectional view in elevationthrough -the centerof thel pump.

Figure 2-is a'sectionalview in elevation through ythe pumpalong the line' 2--2 in Figure l.

VFigure Bis` a. sectional view in elevation through .one side offthepump along the line 3-3 in Figure l 1.

'Figure 4 is a horizontal sectional view through another sideof the pump along the line 4-4 in :Figure `1.

.Figure 5 is a sectional view, in elevation through another sideof theypumpalong the line 5-5 in A `Figure 1.

.of the rotary c ammechanism.

Figure. shows the same threeelements of the .cam mechanismy assembled together and in their relative` positions` with respect to each other when the-lead piston is in full strokeposition.

(Cl. 10S-161) 'I'he pump is assembled in a housing I0 which remains stationary after the pump is aligned and fastened to a motor by coupling or axle Il. The pump is supported inside housing I by pressure bearing I2, and ball bearings I3 and I4 on the suction side of the pump., Bearing I5 as part of a. thrust bearing only indirectly supports the elements associated along the horizontal center line of the pump. Suitable and necessary fittings and packing to seal the fluid within the system and at the same time allow the pump to rotate freely are shown though not described lhere in detail.

The pump of this invention may have any f number of cylinders in single or multiple rows.

In the drawings a flve cylinder rotary pump is illustrated. An inclosed cylinder IG and a sectipnal View of cylinder I8 are shown in Figure l, while cylinders I6, I1, I8, I9 and 20 are shown in sectional Lviews in Figure 2. The cylinders are strengthened in their angular relations to each other by webbing 2l shown only in Figure l.

The piston 22 is illustrated in minimum stroke position within chamber 23. Valve head 24 has closed oi port 25 under the action of coil spring 26 pushing down from cylinder head 2l. Piston 22 is actuated through connecting rod 28 by crank pin 29 and as illustrated has closed port 30. It will be observedthat all of the pistons are shown in Figure 2 in the same position as piston 22 in cylinder I8, which represents the rotary pump in minimum stroke position.

Cap 3l is screwed over sleeve 32 against the force of springs 33 which are compressed between the collar 34 of thrust bearing l5 and the bearing base 35 of roller bearing 36. Collar 34 is securely fastened to cylinder 31 which reciprocates and rotates within definite limits under the pressure of springs 33 and the fluid pressure built up in the pump. The entire thrust bearextends into the pump and holds pin 39. The' purpose of narrowing the cylinder to rod-like proportions is to allow for its extension through the other two elements of the helical cam within thepump. The arrangements of the elements comprising the helical cam and how it functions can be best visualized by studying Figures 'l and 8.

In Figure 7 the elements or parts of the helical cam are shown separated whereas in Figure 8 they are illustrated in associated relation to each other as they would be when crank pin 29 would have moved the master connecting rod 28 and piston 22 into full stroke position, as exempliiied by position of piston, valve and crank pin in Figure 6. The relative positions of the `parts of the helical cam shown assembled in Figure 1 are as they would be when crank pin `28 would have. moved the master connecting rod 28 and piston 22v into minimum stroke position.

In assembling the helical cam, rod 38 is passed into ring 48 whichis held stationary to housing I by teeth 4I. A spiral slot 42 is cut in ring 40 vand another spiral slot 43 is cut in sleeve 44.

Sleeve-44 is adapted to slide over ring 40 and when rotated so that slots 42 and 43 overlap one another, they do so at right angles. Thus it will be seen that rod 38, ring 48 and sleeve 44 telescope each other,v that is to say, ring 40 is' stationary whereas rod 39 ijlts into ring 48 and is rotatable therein, while sleeve 44 nts over ring 40 and is rotatable thereabout. When assembled pin 39 is securely held in hole 45 in rod 38 and extends through slots 42 and 43. Sleeve 44 is closed at one end by head 45 to which crank pin 29 is securely fastened.

Figure 3 is a vertical view of a section of the pump along the line 3-'3 of Figure 1 and shows the elliptical chamber 41 formed in the housing Ill which ,receives fiuid for the pump, the several slots 48 for passing the fluid into circular port 49, and passageways 50 for conducting the fluid from circular port 49 to port 30 surrounding the piston chamber' 23.

Figure 4 is a horizontal View of a sectionI of the cylinder I8 along the line 4--4 of Figure 1 and shows a section of the piston 22, openings I in the wall of the piston chamber 23, circular port 30 which distributes fluid from channel 50 to the several openings 5I around the chamber,

and passageway52 which is a live line of fluid under pressure from the chamber.

Figure 5 is a vertical view of a section of the pump along the line 5 5 of Figure 1 and shows a chamber 53 for holding the iluid under pressure, several openings 54 for passing fluid into circular port-55 and thence to circular port 56, from which port the fluid may be directed through any number of channels 51 to perform work. Any channel not used can be suitably closed by inserting a plug in openings 59 as indicated in Figure 5.

The hydraulic generator of this invention is directly connected by suitablemeans to a motor and is designed so that the cylinders rotate while the housing remains stationary. Fluid is supplied through openings in the housing `tc circular ports which supply the several cylinders in rotation. The fluid is sucked into the cylinders and by reason of poppet valves the fluid is dischargedfrom successive rotating cylinders into a circular port. A detailed description of the passage of the fluid l through the pump, that is from the suction side to the pressure side and on to the several points of use will help to explain the many features of this live line hydraulic generator.

Fluid is supplied-to the pump through the inlet 58 and collects in chamber 41 and overflows through openings 48 into circular port 49. As the cylinders I6, I1, I8, I9 and 20 revolve around axle II which is directly connected with a motor the fluid supplied through circular port 49wi11 flow through passages 50 into port 30 which encircles'pistoh chamber 23. When piston head 22 is retracted within the chamber 23 sufliciently to uncover the openings 5| the fluid will pass from port 3l) into chamber 23. On the return stroke piston 22 will seal oi openings 5I to port 30 and tend to compress the fluid in chamber 23. As the compression stroke continues the fluid will press against valve 24 and cause the spring 26 to compress. As the valve head 24 recedes it will uncover port 25 which encircles the upper part 5 under pressure into circular port 55, which encircles axle II of the rotatingpump, and thence into another circular port 56. The uid under pressure finally fills passages 51 and as the pressure is built up by the pump the fluid -is ready to vperform work by transmitting its pressure through the rseveral openings 59.

It should be understood that the inventor has only described in detail the various elements of cylinder I8 and the different parts of the pump for supplying and controlling the .passage of fluid i through 'that master cylinder of the pump. Likewise the description of the flow of fluid through the pump was confined to the parts of the pump common to al1 cylinders, and through cylinder I8.

:n A11 of the other cylinders will have the same elements and detail of construction, also the fluid will travel identically as described through each and all of thel cylinders of the pump. However, the foregoing description of the various elements '25 of the pump and-the flow of fluid through the pump should not be understood as describing a static condition, where the fluid flows under the influence of gravity. It should be recalled at this point that the hydraulic generator of this invention has been designed for direct connection to high speed motors to produce pressures all the way up to three thousand pounds per square inch, and4 more. l

As the generator rotates at high speed a dynamic condition exists that Vis utilized by the inventor in at least two beneficial ways. In the flrstplace the centrifugal influence will supercharge the piston chambers with fluid and therebyincrease the efficiency of the pump. In the second place the cranking torque, which is always tending to force the master piston into zero stroke position, increases as the pump builds up pressure, so that there is a constantly increasing dynamic tendency to overcome the resistance of springs 33, and when it does,'the piston is forced into zero stroke position.

Attention is called here 4again to details of con-H struction of this apparatus which make it possible to use it at such high speeds. Figure 3 shows in detail the induction port which encircles the central shaft of the pump, and the elliptical chamber 41. This port is on the suctionside of the pump and is designed so as to feed all of the cylinders simultaneouslyI intermittently or in any order desired. Figure 4 illustrates an induction port which encircles the piston chamberand very elllciently fills the chamber in minimum time through any number of openings 5I. Figure 5 shows in detail the outlet port on the pressure side o1' the pump which encircles the central '5 of the generator simultaneously, intermittently,

"or in any order desired, as stated. He may likewise utilize the pump pressure vthrough any number of outlets 59 simultaneously, intermittently, or in any order desired, after the desired operating pressure has been once attained.

There is illustrated in the drawings a generally used' type of piston, connecting rod and crankA pin. It is also Within the scope of this invention to use only a crank, instead of the connecting rod and crank pin, to transmit the dynamic pres.

shaft ofI-the pump and chamber 53 which is dis- I sure being built up through the helical cam to compress springs 33. As the pressure against piston 22 builds up sufliciently the crank rotates' pin 29 and at the same time sleeve M. As sleeve M rotates the helical slots 43 guides pin 39 into a helical rotation through ninety degrees, and helical slot 42 in ring 40 guides pin 39 through another ninety degrees of rotating. This rotationand movement of pin 39 is identical with that of cylinder 31 which in turn compresses springs 33 until the piston 22 is in zero stroke position as illustrated in Figures 1 and 2.

As pressure at the numerous outlets of the live line system is used the pressure on piston 22 is lessened and the pressure transmitted through the helical cam against springs 33 falls oil. At a certain point the springs 33 will overcome the pressure against it and will move cylinder 31 forward and in doing so pin 39 will helically rotate through slot 42 in ring 40. Then pin A39 will rotate sleeve M and pin 29 as it continues to helically rotate in slot 43. turned again to full stroke positionas illustrated in Figure 6 and the cycle of operations is repeated as -described as long as the pump is required to keep up pressure in the live line 52 and the system beyond.

Once the generator has built up the pressure desired and there is no work to spend it on the generator continues to rotate but stops pumping.

This is a tremendous advantage in pumps because it avoids wearing lout the vital elements of the pump, such as the lapped cylinders, pistons and ports. The motor or cylinders revolve on their bearings but there is no circulation of fluid. At such times the pump is standing by fora live line noncirculating system of pressure. The instant the pressure falls the cylinders. which have been rotating idly by reason of their direct connection to a motor not shown, will start to generate pressure for the live line system. Thus it will be seen that the generator of the invention 'is in eiect a variable displacement pump which has tremendous advantages over any constant displacement pump. The latter type of pump, exempliiied by the vane or gear types, keeps circulating iluid constantly and wasting energy when in Thus the piston 22 is reailerons, ilaps, raise the lower landing gear, move machine guns, open and close discharge chutes, doors, etc. It could be used'on military tanks for hydraulically moving heavy armament, machine guns and turrets. It could be used wherever a live line noncirculating pressure system within the limits of thegenerator is desirable and there-is a motor available to which the hydraulic generator can be connected. V

Having described my invention, what I claim is:

1. A hydraulic generator comprising a stationary housing, aA rotating group of cylinders co-nnected directly to a rotating means, each cylinder containing a piston chamber, a piston and poppet valve, each piston chamber being surrounded by two separate ports, each piston being joined by a connecting rod to a common crank pin, and a helical cam mechanism for moving said common crank pin eccentrically so as to alter the strokes of each piston.

2. A hydraulic generator consisting of a stationary housing, a rotor connected to rotating A means, a helical cam mechanism actuated by a use, while the amount of pumping performed by the generator of this invention varies with the amount of pressure to be made up after some has been used to perform work. The balance of the time the cylinders rotate idly, use little or no energy and pump no duid.

There are many changes and modifications o the apparatus of this invention which have not been described but which do come Within the scope of this invention. For instance. instead of screwing cap 3| to compress springs 33 a bolt could be screwed into cylinder 31 and by suitable construction compress springs 33 against collar 34. Thus instead of cap 3l pulling against teeth on sleeve 32, we would eliminate the cap and have a threaded bolt'pull against the threaded inside wall of cylinder 31.

Any of the usual types of pumping fluids may be used in the rotary hydraulic generator described, such as water, thin oils, reilned cylinderl oils, etc.

The hydraulic generator of this invention would have numerous applications and uses. It

would be ideal for use on airplanes to operate heavy spring which is regulated by movement of a. cap over asleeve formed by part of said housing, said rotor comprising a plurality of radial cylinders, each cylinder enclosing a chamber, separate circular ports around diierent sections of each chamber, a slidable piston, and a connecting rod, suitable passageways for transferring uid to each chamber through the circular ports nearest the crank pin, and suitable passageways for conducting fluid from each cham--l ber through the circular ports farthest from the crank pin to a common pressure chamber for distribution.

3. A rotary hydraulic generator of the class described comprising a housing, a rotor consisting of several cylinders, a piston chamber and piston in each cylinder, all pistons connected to a common crank, said crank connected to a helical cam mechanism consisting of a rotatable sleeve, a fixed ring, and a rotatable and translatable rod, with a pin fixed therein at the end near the center of said rotor, said sleeve and said ring having overlapping slots to accommodate said pin.

4. An hydraulic generator of the class` described having a housing for the rotor comprising aplurality of cylinders each containing a piston and piston chamber, each piston connected to a common crank, said crank secured to an axial cam, said cam consisting of a slidable and rotatable sleeve, a xed ring, and a. slidable and rotatable rod having a pin fixed therein at the end near the crank, and said sleeve ,and said ilxed ring having overlapping slots for the passage therethrough of said pin.

.f 5. .An hydraulic generator of the class described having a housing for the rotor comprising a plurality of cylinders each containing a piston and piston chamber, each piston connected to a co'mmon crank, said crank secured to an axial cam mechanism consisting of a slidable and at the same time rotatable sleeve, a xed ring, and a slidable and at the same time rotatable rod, said rod having a pin in the end near the. crank, said sleeve and said ring having helical slots adapted to permit the passage of said pin simultaneously therethrough.

EDWARD W. MCDONOUGH.

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