US2608158A

US2608158A - Pump

Info

Publication number: US2608158A
Application number: US55742A
Authority: US
Inventors: Beaman Bernard; Hulman Julius; Robert A Stein
Original assignee: HULMAN
Current assignee: HULMAN
Priority date: 1945-06-08
Filing date: 1948-10-21
Publication date: 1952-08-26
Anticipated expiration: 1969-08-26

Description

Aug- 26, 1952 B. BEAMAN ET AL 2,608,158

PUMP

Original Filed June 8, 1945 19 jygjj a w l 5 l.

Patented Aug. 26,` 1952 sei-nua mman, Julius nulnml, and neben A. Stein, Dayton, Ohio; said Beaman and said Stein signora to said Hulman original application .inne s, 1945, serial No. 598,356. Divided andthis application Octolle'l zr, 194s, serial No. 55,742

z claims. lol. los-'162) (Granted :maary che act or Maren s, lsss, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

Our present invention relates in general to a hydraulic pressure pump of two-stage character such as disclosed in our copending application, Serial No. 598,356, filed June 8, 1945, which matured into Patent No. 2,495,685, on January 31, 1950, from which this application is a division; Thepump there shown v is designed for efiicient operation at extremely high pressures in the second stage. I

One object of the present invention is to provide a pump structure of the type having a rotating barrel provided with cylinder bores 'in which pistons are slidable by engagement with.

a cam, wherein an increased pressure thrust 'of the cylinder barrel against a valve plate isv secured by reducing the unseating pressure force' on the area' between the barrel cylinder openings and the barrel land area, such construction involving a-vaive port diameter less than lthe cylinder circle diameter and permitting of multiple drilled passageways from the ends of the cylinders to the valve ports so that the fiw area can be made the desired value, and the drilled passageways being at an angle produce an elliptical intersection between the drilled passageways and the valve ports in a plane face at the end of the cylinder barrel.

With this main object in view, as well as other' nlinor obects that will be developed as the del one of its ends for mounting the pump on an air craft engine or the like.A For this purpose bolts or screws may extend through suitable perfora- 1 tions of the ange I2 and thread into the engine or any suitable Support in the usual manner.

scription ofv our invention proceeds, the construction, arrangement and combination of thevarious parts of our pump structure will hereinafter be more fully set forth, pointed out in our claims and illustrated in the accompanyin drawings. wherein: A

Figure 1 is a vertical sectional view through a pump structure embodying our present invention and corresponds in general to Figure 4- vof our copending application with the porting arrangement of Figures 15 and 16 thereof applied to Figure 4.

Figure 2 is a sectional view on the line 2--2 of Figure 1 taken at the parting face between the housing and the end plate of the pump and 0n the accompanying drawing, we have used The housing I0 'has a flange I8 at its other end to which an end plate I8 is secured as by cap screws 20 with a 'suitable gasket or sealing conpound between thev iiange IB and the end p a e.

The housing I0 has an internal partition 22 against which a back plate 23 is positioned and secured in such position. A cam 24 is aiiixed to the back platev23 so as to be stationary in relation thereto.'v The cam iits the interior of the housing I Il and is retained against rotationby a pair of dowels I9 and 2i. The cam 24 has a cam face 28 which is inthe form of a truncated cylinder end, and a hardened creep plate 30 of vasher-like character for engaging against this ace. -4

Rotatable in a bearing sleeve 32 of the end plate I8 and in a bearing surface 34 of the cam 24 is a barrel drive shaft 3E. Loosely splined at 42 on the barrel driveshait 38 is abarrel M having an annular shoulder t8 engaging the shaft 36 for guide purposes. The barrel 44 has a pair of annular lands 50 and 5I to contact with a ilat sealing face 52 of the end plate I8. The loose splining of the brrel 44 to the shaft 36 permits ready conformity of the lands 50 and 5i to the face 52. l

vCircumi erentially spaced cylinder bores 54 are provided in the barrel 4 4 and in each a plungerlikepiston 56 is reciprcable. The cylinders 5l and the pistons 56 constitute a high pressure pump. Each cylinder has a pair of cylinder ports 58 which are of somewhat less cross sectional area than the area of the cylinder bore in order to provide the necessary thrust force between the barrel 44 and the end plate I8 by internal pressure acting on the cylinder bore ends surrounding the ports 58.

The barrel 44 is adapted to be seatediagainst the end plate I8 by hydraulic pressure withinthe pump housing I0 as :will hereinafter appear, During starting of the pump, when pressure has not yet built up, it is desirable to make sure that the faces 50 and 5I are in contact with the face 52 and this may be accomplished by a light spring 59. i,

A low pressure pump is provided in the form of a rotor 38 having slots in which vanes 4I are 3 slidably mounted. the rotor being within a stator bore 80 of the c'am 24 which stator bore is eccentric with relation to the rotor to thereby effect inward and outward movement of the vane's 48 in a well-known manner and as disclosed in our parent application.

A low pressure inlet boss 82 is provided on the end plate I8 and communicates with a passageway 44 in the end plate which in turn communicates with an intake passageway 88 in the housing |0. The passageway 88 communicates with the interior of the dowel 2| through openings 88 therein and the interior of the dowel communicates with an intake port 10 formed in the back plate 28. 'I'his port feeds liquid into the intake side of the low pressure pump (lower side in Figure 1).

An outlet port 12 is provided on the high pressure side of the lower pressure pump and this outlet communicates through openings 14 in the dowel i8 with an outlet passageway 18 which extends to the inner face 52 of the end plate I8 and communicates with a C-shaped passageway 18 formed at the end of the housing |0 adjacent the plate 8. The passageway 'I8 communicates with an arcuate intake port 82 of the end plate I8 as shown by dot and dash lines in Figure 2 and in greater detail in our parent application so that oil can be drawn into the cylinder bores 84 through the ports -58 when they register with the port 82. the intake port 82 of course being for the high pressure pump.

The ports 58 successively register with an outlet port 84 (also shown by dot and dash lines in Figure 2) which is also arcuate in shape and communicates directly with an outlet or high pressure boss 88 on the end plate I8. The boss 88 is the outlet and the boss 62 is the inlet and accordingly there is low pressure in the boss 82 and high pressure in the boss 88 as indicated by the legends HI and LO adjacent the arrows in the bosses 88 and 82, respectively in Figure 1.

The dowel I8 is threaded in position and canl accordingly be removed. The dowel 21 is also removable so that the pump action may be reversed by reversing the plate 23 in the housing I4 as fully explained in our parent application.

The rotor 38 is formed on a shaft |04 which rotates in a bearing surface |08 of the back plate 28 and is connected to the barrel drive shaft 38 by a loosely splined connection |08 and with a drive shaft by means of a loosely splined connection ||2. The drive shaft ||0 has a splined end ||4 for connection to a power takeoif shaft of an aircraft engine or any other suitable means to drive the pump. Such means would align the outer end of the drive shaft ||0 for proper operation without binding.

The drive shaft ||0 has a flange ||8 surrounding it with which a seal plate ||8 in the form of a ring is engageable. A spring |20 effects such engagement initially, whereas uid pressure within the housing effects the engagement after the pump is in operation. The spring |20 is seated against a second end plate |22 secured to The seal plate ||8 is sealed relative to the housing |0 by means of a diaphragm 28 having its inner end clamped to the seal plate by a spanner nut |28 and its outer edge clamped between a washer |30 and the end plate |22 by the screws |24. This provides a pressure chamber indicated at |32 inside of the flange ||8.

the partition 22 by suitable means such as screws against a shoulder |84 of the rotor shaft |04 which serves merely as a thrust connection but normally when the pump is operated the two are spaced from each other. A passageway |38 is provided through the center of the rotor shaft and communicates with a passageway |88 through the center of the barrel shaft 88 through which liquid is adapted .to ilow after passing through the splined connections ||2 and |44. A relief groove |40 is provided for such flow in the event that the inner end of the drive shaft ||4 is seated against the shoulder |84.

'I'he low pressure pump comprising the rotor 08 and the vanes 48 is higher capacity than the high pressure pump comprising the cylinders 84 and the pistons 88. This is for the purpose of assuring full charge of the high pressure cylinders for reducing voids in the liquid and for keeping the pistons in contact with the creepplate I0. To avoid excessive build-up of pressure and to keep a substantially even charging pressure from the low pressure pump to the high pressure pump. a relief valve from the outlet of the low pressure pump to its inlet may be provided as disclosed in our parent application.

The porting arrangement 88 is the main feature of our present invention, the other features thereof being claimed in our parent application. These ports, it will be noted. are drilled at an angle instead of extending axially into the ends of the bores 84. 'I'his results in their outer ends terminating in elliptical port openings as shown in Figure 2 which are closer to the center of rotation than the axes of the cylinders 84. This provides increased pressure thrust of the barrel 44 against the valve plate 8 as it reduces the unseating pressure force on the area between the barrel cylinder openings and the barrel land 'area. This is basically produced by reducing the radii of the ports 82 and 84 in the end or valve plate I8 so that their diameter is less than the cylinder circle diameter.

Any number of the ports 88 may be used (two are shown by way of illustration) per cylinder as required to provide the desired flow passage. The barrel is preferably provided with a pair of circular lands instead of having a plane face, thesebeing the lands indicated at and 8|. The land 80 is in alignment with the cylinder circle diameter and thus acts as a stabilizing land. The land 8| for the ports 88, 82 and 84, it will be noted, is brought inside the cylinder circle diameter.

Practical operation causes liquid to be drawn in from the intake boss 82 through the passageways 84. 88. 88 and I0 to the low pressure pump. The liquid therein is pumped out through the

passageways

12, 14, 18.

'Ihe inner end of the drive shaft |0 is seated 75 18. 80 and 82 to the pistons 88 on their inward strokes while their cylinder ports 58 communicate with the intake port 82.

Rotation around the other half of the circle causes the pistons to be forced outwardly in the cylinders 54 (see upperpiston in Figure 3) for forcing the oil into the high pressure outlet passageway 84 and the outlet boss 86. The liquid is thus pumped at low pressure by the vane pump and at high pressure by the piston pump which is charged by the lower pressure vane pump, and the pressure in the outlet 86 may be relatively high such as 3,000 pounds per square inch in the particular design of pump illustrated.

During operation the spring 59'keeps the barrel 44 in engagement with the end plate I8 and the spring |20 keeps the seal plate I |8 in engagement with the flange I I6 so that there is a sealed. cham- :ber within the housing I extending from the end plate I8 to the diaphragm |26. These springs, particularly the spring 59, maintain the seal necessary for priming the pump. There is some leakage of liquid past the faces 50, and 52, especially before pressure is built up in the housing I0 and this liquid together with the small amount which creeps past the pistons 56 and any which may leak from the low pressure pump will charge the interior of the housing I 0 for lubricating the bearing surfaces 32, 34 and |06 and pro-- duce a pressure within the housing.

The barrel 44 will be seated against the end plate I8 under the action of the charging pressure for the housing plus the internal pressure of the cylinder bores acting cn the partially closed cylinder ends. The pressure also acts on the flange 80 to compress the spring |20 somewhat and thereafter maintain the ange |I6 against the sealing face of the seal plate ||8 under such pressure. The pressure is limited however by the relief valve |42 beyond the strength of the spring |46. The liquid pressure will move the relief valve to a relief position permitting the excess liquid to flow through the ports |54, |56 and |58 back to the lower pressure boss B2. A selected spring |46 may be used as required to keep a desired pressure within the housing. The valve |42 therefore acts as a pressure regulating valve.

Our two-stage pump can lbe readily adjusted for a reversal in the direction of rotation by removing the dowels I9 and 2|, rotating the back plate 23 a half turn and re-inserting the dowels in the manner described in our parent application.

From the foregoing specification we believe it will be obvious that We have provided a structure which compactly includes both a low pressure pump and a high pressure pump whereby a. complete hydraulic pump suitable for'high pressure operation is had. Increased pressure thrust of the barrel 44 against the end plate I8 is had by reducing the unseating pressure forces at the parting line between these two elements. This is accomplishedfby reducing the circle diameter of the ports 58 to less than that of the cylinder bores in the novel manner disclosed. This also has the added advantage of reducing the circle diameter of the ports 82 and 84 and permitting the use of multiple passages 58 which are slightly increased in area at the ends thereof where they match the ports 82 and 84 by being 6 drilled at a slant so as to be elliptical rather than truly round in cross section at their terminal ends at the land 5|.

Some changes may be made in the construction and arrangement of the parts of our pump without departing from the real spirit and purpose of our invention, and it is our intention ,tov

cover by our claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We claim as our invention:

l. In a hydraulic pressure pump of the character disclosed, a housing, a Ibarrel driving shaft journalled therein, a barrel loosely mounted on said shaft for rotation therewith and ibeing provided with cylinder bores, an end plate for said housing, said barrel being engaged therewith under iiuid pressure against partially closed ends of said cylinder bores, pistons in said cylinder bores. a cam for reciprocating said pistons, said end plate having -ports and said barrel having inwardly slanting openings for providing fluid communication between said cylinder bores and said ports in said end plate terminating at the end of said barrel in alignment with said ports, said barrel having a continuous uninterrupted circular land at the cylinder circle diameter and a second circular land of smaller diameter at the terminals of said slanting openings.

2. In a hydraulic pressure pump of the character described, a housing, a barrel driving shaft journalled therein, a Ibarrel on said shaft, an end plate having a fiat surface against one end of said housing, said barrel lbeing engaged with said nat surfae and having a plurality of cylinder Ibores, lpistons therein, a cam for reciprocating said pistons, said end plate having C-shaped inlet and outlet ports for said cylinder bores arranged on a circle smaller than the cylinder bore circle diameter, said barrel having connecting slanting passages extending in straight direct lines from said bores to the end of said barrel where they register with said ports and a pair of circular lands, one coincident with said smaller circle and the other coincident with said cylinder bore circle diameter.

BERNARD lBEAIMAN. JULIUS HUIMAN. ROBERT A. STEIN.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,822,064 Sorensen Sept. 8, 1931 1,867,308 Durner July 13, 1932 2,015,423 Flanders Sept. 24, 1935 2,069,651 Ferris Feb. 2, 1937 2,292,125 Ifleld Aug. 4, 1942 2,331,694 Jerey Oct. 12, 1943 2,419,600 Sejarto Apr. 29, 1947 2,445,232 Molly July 13, 1948 2,495,685 Beaman et al. Jan. 31, 1950 FOREIGN PATENTS Number Country Date I Great Britain 1941