US2403292A - Hydraulic pump - Google Patents

Description

w. MESSINGER HYDRAULIC PUMP July 2, 1946.

Filed May 9, 1945 2 Sheets-Sheet l ENTOR. Jrz'sswai/P w. MESSINGER 2,403,292

HYDRAULIC PUMP Filed May 9 1945 July 2, 1946 INVENTOR.

2 Sheets-Sheet 2 Mum/w Mgsswam ATZUEZVEY Patented July z, 1946 UNITED STATES PATENT OFFICE isfit...

William Messingcr, Philadelphia, Pa. Application my 9, 1945, Serial No- 592,831

This invention relates to a power operated hydraulic pressure pump, and has for one of its,"

principal objects the provision of a relatively small, light-weight structure capable of delivering a fluid stream at exceptionally high pressures on the order of 30,000 lbs/sq. in. and more. Such pumps may be utilized for the operation of a great variety of hydraulic devices such as lifting jacks, punches, presses and forcing implements. 7

More particularly, this invention relates to pumps wherein a swashplate is employed for the purpose of transforming circular motion'into reciprocating motion for operating pump plungers. It is a further object of this invention to transmit the power to the plungers and to effect the conversion of circular motion into reciprocating motion by means of a 3-way bearing capable of taking up forces radially, as well as in opposite axial directions. By reason of this construction, a simplification has been achieved over other pumps of "this type, resulting in greatly condensed structure and reduced weight so that the unit is readily portable while capable of delivering exceedingly high pressures.

It is a further object of this invention to provide a swashplate type pump which is doubleacting, that is, plungers are disposed on both sides of the swashplateand certain of the plungers are operated on their power strokes while certain other plungers on the other side of the swashplate are operated on their suction strokes. This feature is made possible by the fact that power is transmitted to the swashplate through the bearing, whereas heretofore such power has been transmitted through a connectionto one face of the swashpiate. I

It is a further object of this invention to provide a bearing as described above which takes the form of an X-bearing. More specifically, the X-bearing has its inner race fixed to the rotating drive shaft, its outer race fixed to or formed integral with the swashplate and held against rotation, and its raceway inclined with respect to the axis of rotation of the drive shaft. In this way gyration is imparted to the swashplate, such gyration having two-way axial components which are utilized to eflect the power and suction strokes of doubleacting plungers on opposite sides of the plate.

In the pump described, circumferential passages are provided in the cylinder block, each such passage being adapted to communicate with a plurality of other passages. It is another object of this invention to provide a novel method and means for forming such passages.

Further objects and advantages of this invention will become apparent in the following detailed description thereof.

In the accompanying drawings,

Fig. 1 is a vertical section through the pump assembly taken substantially on the line i--l of' Fig. 3. a

Fig. 2 is a partial section taken substantially on the line 2-2 of Fig. 3 showing the arrange-,

ment of fluid suppl and discharge passages.

Fig. 3 is an endview of the Fig. 1 assembly. Fig. 4 is an enlargement of a portion of Fig. 1. Referring to Fig.1. of the drawings, there is shown the power driven hydraulic pump embodying this invention, and comprising three main :parts as follows: r 1 A. A power element for delivering rotary motion to a power shaft. g

'B. A transmitter and converter element for transmitting power from the power shaft to the driven members and for converting circular motion into reciprocating motion. C. A pump element driven by the power element through the transmitter and converter element.

A. The power element correspondingly high torque. The pump shaft 22 extends into the casing 30 of the pump element.

plungers and cylinders being so positioned as to provide overlapping and, hence, smooth discharge fromthe pump. o

B. The transmitter and converter element The power from the power element is delivered by way of power shaft l0, reduction gear 20 and pump shaft 22 to the pump element by way of the transmitter and converter element. This element in my invention takes the form of an X-bearing consisting of an inner race 40, an outer race II and rollers 12. The inner and outer races have cooperating race-ways in the form of circumferential grooves formed by walls at an angle of with respect to each other. Certain rollers roll upon one wall 48 of one groove and upon the M cooperatingconcentric wall II of the other groove,

revolution of the inner race.

' the power element to the pump element and converting-'circular motion into reciprocating motion, my "construction provides the following;

First, instead of mounting the X-bearingon the shaft 22 so that the plane of rotation of the races is normal to the shaft axis, I mount the X-bearing so that the plane of rotation thereof is inclined to the axis. Second, by holding the outer race against rotation, it will be given a gyrating, oscillating or wabbling swashplate .motion as the inner race rotates. By providing an extension 50 on the outer race, either by fixing a flange theretov or forming the flange integral therewith, there is obtained a swashplate every point of which is reciprocated axially during each The X-bearing thus not only transmits the power from power element A to the swashplate, but also converts the circular motion of shafts l and. 22 into the by' creating a vacuum betweeii a pressure check valve ill at the inner end of the cylindenthroughthe cylinder to the inner end of plunger 6!. This vacuum draws fluid from the reservoir, assisted by gravity, through reservoir duct 82 (see Fig. 2)

which is protected by washer and tubular packlugs 83, through passages 84, 85 and 86. to a circumferential inlet slot 16. Two such inlet slots are provided, one on each side of the swashplate, 'to cooperate with the set of cylinders on the respective side, the two inlet slots being connected by a passage 81. Each slot 16 communicates with its respective cylinders by-meansof drilled holes 88.

These slots or gashes 16, after being machined into the pump block or casingSO, are sealed peripherally bya wire inlay 89 which is welded into position to prevent leakage.

As each plunger is drawn out of its cylinder, it

draws fluid from the reservoir through the sysfluid from the inner end of the pistonup to the reciprocating motion of any point on the swashplate. This reciprocating movement is utilized for actuating the pumping members of thepump element C.

C. The pump element The-swashplate 50 is connected through universal joints 55 with a plurality of plungers 60,

El operating in cylinders ill, H bored within the check valve 8| which closes the inner end of the cylinder. A suction packing 90 (see Fig. 4) is provided to maintain the seal surrounding the pump .plunger, preserving the vacuum, and insuring complete filling of the cylinder and the z intervening spaces ahead of the plunger.

illustrating one form in which four are employed.

The plungers are thus constrained to axial move-' the gyrating, reciprocating movement of theswashplate. Such movement develops a radial component of motion with respect to the pump plungers. This radial movement is permitted by the ball and socket tappet arrangement fastened to the dual pump plungers and comprising screwed-on, concave socket members 56 and oscillating, ball-shaped levelling washers 51 pro-- viding a central aperture 58.

The axial components of the gyrati'ng move-.

ment are caused to operate the plungers axially. A pair of plungers is connected to the same universal joint on opposite sides of the plate so that the piate is double-acting in that it operates one plunger on a, power stroke while operating the other plunger on a suction stroke. Two sets of plungers are arranged concentric with shaft 22 in opposed relation on opposite sides of the swashplate, and the number of plungers and cylinders is so chosen. that the discharges overlap to even out the discharge pulses and yield substantially smooth flow.

Fig. 1 shows two opposed plungers 80. 6| connected to swashplate 50 by a universal connection 55;

completed its suction stroke in cylinder 1 I. The latter stroke ha sucked fluid from reservoir 80 On the power stroke of each plunger, it enters a pressure packing 9|, compressing the fluid ahead of it and expelling the fluid under pressure through the respective check valve 8 i The check valves at the left are connected by drill holes 92 to a circumferential delivery slot 93, constructed in the same manner as inlet slots 16. The collected discharge fluid is delivered to a chamber 94, and thence by a connection 95 is'delivered to a fitting 98 where it joins the discharge from the cylinders on the right-hand side. The discharge from the latter cylinders passes by radial passageways 96 to the delivery pipe 91.

In accordance with the provisions of the patent statutes. 1 have herein described the principle and operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other equivalent means. Also, while it is designed to use the various features and elements in the combination and relations-described, some of these may be altered and others omitted without interfering with the more general results Plunger Gllhas just completed its power stroke in cylinder 10,-and lunger 6| has just Having described my invention, what I claim and desire to secure by Letters Patent is:

l. A power driven hydraulic pump comprising a power element, a shaft rotated thereby, a

pump element, means whereby the shaft operates the pump element, a source of fluid supply, the

pump element comprising a pump body having a plurality of cylinders therein arranged symmetrically around the axis of the shaft, the body having a peripheral cut forming'a circumferential passage, the body having an inlet passage for leading fluidfrom the source to the circumferential passage, the body having drill holes leading from the cut to the individual cylinders, the out being sealed by a peripheral insert.

2. A powerdriven hydraulic pump as specified in claim 1, in which the cut is sealed by a, strip of material welded therein.

3. A power driven hydraulic pump as specified in. claim 1, in which the body hasa plurality of discharge passages, a second circumferential cut pump element, a source of fluid supply, the pump element comprising a pump body having a plurality of cylinders therein arranged symmetrically around the axi of the shaft, the body having a peripheral cut forming a circumferential passage. the body having an inlet passage from the fluid supply to the circumferential passage and drill holes leading from the cut to the individual cylinders, the body having a plurality of discharge passages leading from the individual cylinders. the body having a second circumferential cut and drill holes connecting the discharge passages to the second circumferential cut, and a single high pressure outlet connected to the 10 discharge passages.

WILLIAM MESSINGER.

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