US 3199417 A
Description (OCR text may contain errors)
Aug. 10, 1965 A. H. YOUNG ETAL DISPERSION BAFFLE FOR AIR-OIL TANK Filed April 27. 1960 United States Patent 3,19,417 DISPERSION RAFFLE FOR AIR-OIL TANK Alan H. Young, Redford, and Merritt B. Sampson, Shaker Heights, fihio, assignors to The Manufacturing Corporation, Solon, Ghio, a corporation of Ohio Filed Apr. 27, 196i Ser. No. 24,981 13 Claims. (Cl. 92-) This invention relates to fluid orientating systems, and more particularly to an orientation system for oil entering an air-oil tank used to provide oil under pressure for hydraulic work cylinders.
Most manufacturing establishments have compressed air from a central system extending to various parts of the plant. Very few plants have oil under pressure derived from a central system. Whenever linear movement is required, and an oil operated cylinder driving a ram is chosen as the proper drive mechanism, the engineering decision involved is whether to employ an oil system pump for the local area, or to employ local oil reservoir tanks operated by air pressure exerted on the oil in the tanks. The latter choice is becoming increasingly popular because it is far the less expensive mode of supplying rapidly cycling hydraulic systems with suitable oil for driving the system. Thus, whenever it is desired to operate a cycling oil operated cylinder, two small container tanks are equipped with bottom outlets connected to suitable lines, leading to opposite ends of the cylinder. Air lines enter the top of each container tank. Then, to move the ram, air is valved into the top of one of the tanks to drive the oil out of the tank to one end of the cylinder. Air is exhausted from the other tank. The tank which is exhausted of its air is a receiving tank for oil exhausted from the cylinder; this cycle is reversed to move the ram the other way.
It is the exhausting of oil from the cylinder into the .bottom of the tanks that provides the difiiculty in such systems, This oil is returned at a very rapid rate through a relative small port and will churn wildly as it enters the tank, unless it is quieted in some manner. If it does churn, it will aerate, with the attendant compressibility problems among others; it will also splash to the top of the tank and become entrained in the air lines. Then, as the exhausted air leaves the tank, the entering oil splashes to the top and some gets entrained with the exhausting air and flows out through the muffler onto the floor of the area surrounding the machine.
Although prior attempts have been made to quiet this oil entry by means of battles, no really successful bafiled tank has been developed prior to this invention. Investigation of the problem of the oil entry has led to the present invention wherein the oil is disrupted in its entry path by a conventional solid bafile and caused to flow laterally towards the sides of the tank. However, the oil flowing laterally pauses through an orientation system which is essentially a screen device causing the oil to break up into laminar columns of individual streams. Thus, although the eye detects only a laterally moving, more or less congealed stream of oil, this oil actually consists of many tiny streams all orientated and going in the same direction.
The orientation system inherently causes some of the oil to slow down in its speed of lateral movement and, therefore, some begins to rise. Some of the oil will continue on at a rapid rate and will actually strike the side of the tank, wherein it then loses more of its energy; and then begins to rise. That portion which slows down before striking the side of the tank is then orientated through a planar screen which substantially covers the bottom of the tank above the lateral screen and causes the oil to.
begin rising in a multitude of small columns. That oil "ice which strikes the side of the tank will tend to take on a swirling movement; but as it passes through the planar screen, it too is caused to assume a laminar flow. Hence, the entire body of oil, after it has been screened laterally and vertically, is quieted and distributed over substantially the entire bottom of the tank and caused to rise as a mass of individual small columns of oil all going the same direction at about the same speed; and the result is that the surface of the oil is quiet to such a great extent that it has the visual appearance of a jelly material sWell ing up into the tank on a perfectly flat plane. No evidence of churning, aerating or splashing of any sort is evidenced.
Therefore, one of the principal objects of this invention is to provide orientation of the flow of oil into an air-oil tank, which will induce a quiescent surface on the oil as it moves within the tank, even with oil flow of 15 feet per second in the lines entering the tank.
Another object of this invention is the provision of an orientation means for an air-oil tank which will pro mote laminar flow of the oil as it enters the tank by dividing the flow into small orientated streams.
A more particular object of this invention is to provide an orientation member for an air-oil tank which is perforate to promote laminar flow and thus induce a quiescent surface condition of the oil in the tank.
Still a further object of this invention is to provide an orientation system for an oil tank which will pass oil through a series of apertures and thus reduce a turbulent condition to a quiescent surface condition by promoting laminar flow.
In addition to the foaming eifect caused by the churning and spashing, hydraulic oils release bubbles .and create foam when they are pumped rapidly through piping. It is possible to provide tanks large enough to prevent foam entrapment into exhaust lines without any foam suppressors, but compressed air is expensive, and a large air space requires much more air. The number of cycles of such equipment is large, and over a period of time a very small extra air requirement will be accumulative to the extent of requiring extra air compressor capacity.
Accordingly, it is a prime object of this invention to provide a maximum useful oil space in such tanks to hold air requirements to a minimum.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawing, in which:
FIGURE 1 is a front elevational view partially in section and somewhat schematic of a two-tank oil-air system connected to a work cylinder and including a valve mechanism for the entrance and exit of air into the tanks;
FIGURE 2 is a foreshortened sectional view of one tank showing details of the orientation member and air baiiie arrangement within the tanks; and,
FIGURE 3 is a sectional view of one tank showing an alternate embodiment of an orientation member.
Referring now'to the figures, this invention is shown and described in the typical environment of a two-tank, air-oil system. This invention is not limited to such systems, but is best depicted in such an environ-ment.
Since each of the tanks are identical, but one will be described, and the other referred to with prime numbers when necessary The tank 1% has a lower head 11, and an upper head 19. The lower head 11 has a port 12 for oil and the upper head 19 has a port 15 for air. Oil is shown in the tanks of FIGURE 1, but omitted from the other illustrations.
A pipe 16 is connected to the air port 15 and provides an entrance and escape passage for operating air. The tanks iii, 10' function to drive a hydraulic work cylinder 40. Cylinder '40 has a piston 41 and a ram 42 carried by the piston. The piston 41 divides an internal chamber 45 into first and second chambers 46, 47. A pipe 43 interconnects the first chamber 46 with the one tank 16, and a pipe 44 interconnects the second chamber 47 with the other'tank 10'.
To complete the system a conventional four-way air valve 30 is provided alternately supplying and relieving ,air pressure on the tanks lit), It).
In operation, when compressed air is forced into the top of one tank I the oil 65 is forced into the first chamber 46 through pipe 43 and drives the piston 41 in the work cylinder 4%. As the piston 41 is moved in the work cylinder 46, it forces the fluid 65 that had been in the second chamber 47 through pipe 44 into the other tank 10'. As the oil rises in the tank 1%, it forces out the air. When the piston 41 reaches the end of its stroke in one direction, the valve rotates and the cycle reverses.
As oil flows from a line into a tank, there is a strong propensity toward turbulence. The oil splashes violently and as a result enters the air lines and the exhaust muffier, despite protective baflles over the air line entrance. The new and improved orientation member prevents aeration and splashing and promotes a smooth laminar flow of the oil.
The orientation members in each tank are identical, so but one will be described. Referring now to FIGURE 2, the orientation member 5% has an imperforate central disc 51. The central disc 51 is placed adjacent to, and completely spans, the opening 12. This disc interrupts the entering oil and causes a distributed lateral flow, usually a plain disc normal to the increasing flow will suflice to produce a reasonably uniform distribution throughout a full 360 degree pattern.
The orientation member 50 includes an extension of the disc 51 in the form of perforate outer ring 52.
For convenience of manufacture, the outer ring 52 is obtained by placing a screen disc 53 and the imperforate disc 51 together in axial alignment. Screen disc 53 is preferably substantially as large as the inside diameter of the tank walls. Thus, the two discs form an imperforate baifle with an outer perforate ring. All oil is diverted laterally by the imperforate baille, and must thereafter pass upward through the screen outer ring.
The combination of discs 51 and 53 will serve to quiet the oil to a considerable degree, but not to the extent provided by the entire combination. A most remarkable quieting is obtained if the flow is given a preliminary orientation prior to rising through screen ring 53.
To produce the preliminary orientation, the orientation member 50 includes a vertical wall screening device 58 surrounding the port 12 under the baffle 51. One cylindrical vertical perforate wall will serve under some conditions, but once again, an unusually greater benefit than expected was obtained by use of multiple vertical walls. Two have been found to be satisfactory for most conditions.
Also for manufacturing convenience, the two Walls are provided by making the member 58 of one piece of screen with a central disc area 57 and a peripheral U-shaped trough portion 54. The disc area 57 is axially aligned with the discs 52 and 53, and the apex of the trough abuts the inside wall of the head 11 in a position circumscribing port 12.
The screen used for disc 53 and member 58 may be Woven, punched, or even slotted. Its purpose is to cause small stream laminar flow.
Air entering port 15 will cause undue aeration and turbulance if allowed to impinge on the oil, and hence port 15 is baflled. Prior solid baflles present a smooth surface where oil bubbles can break and collect as a fine film to be picked up by exhaust air streams. It has been found that by using a screen batfle, the oil bubbles that do reach the bathe break and collect in the screen interstices until a drop is formed. The drops are usually too large to be taste entrained in the exhaust air, and the exhaust air does not have the opportunity to reach them as well. For convenience and to produce a good air distribution, the member 50 is used over this port also. Furthermore, by the use of the identical member St} at both ends of the tank, the tanks are reversible to use either end as an oil or air inlet-outlet. Thus, whenever it is desired to place a sight gauge in a more convenient location, it is not necessary to convert the sight gauge, but the tank may be merely reversed. Also, such duplicate construction on each end makes impossible the use of a Wrong end as an air or oil attachment end. The two opposed members 50 are held in operative relationship quite conveniently by the use of a central post 45 threaded on each end, and a nut 4-6 provides an abutment shoulder. Discs Si, 53, and central disc area 57 of member 58 are pierced axially and the end of post 45 extends through these aligned pierced openings. By adjustment of nuts 46 the apex portions of the opposed members 58 abut the opposed internal walls of heads 11 and 19 to press the opposed members Eil against nuts 46. Thus, the members 51 are held in operative position Without using internal fasteners.
The oil entering the tank through port 12 is in a turbulent and agitated state as a result of pressure and flow. Disc 5'7 is the first portion of the orientation device that the flowing oil encounters. The oil is diverted laterally and then flows through openings formed in the vertical legs provided by the U-shaped trough of member 58. In flowing through such openings, there is a preliminary orientation to laminar flow. Some of the oil striking baflle 51 will be slowed down more than the remainder. The slower moving oil flows through one leg of U-shaped section of member 558 and upward through the outer ring portion of disc 53. Slowing, and flow through screen openings, orients movement of the oil to produce a laminar flow. Thus, the result is a quiescent surface on the oil as it rises in the tank.
The faster moving oil will pass through both legs of the U-shaped trough and thence upward through the section 53. Thus, after passing through the member 53 there are more openings to promote a laminar flow of the oil resulting in a quiescent surface. Some oil will be flowing so rapidly it will hit the side of the tank and rebound before passing through the openings in disc 53. Thus, the orientation device provides a conventional baffle to redirect the oil, and then provides progressive stages of orientation and distribution resulting in a distribution of vertically rising columns of oil, with the result that the oil is absolutely calm as it rises in the tanks with no oil being entrained in the air exhaust.
Oil will flow in piping without undue turbulance up to about 15 feet per second. Above this speed cavitation takes place and will create small bubbles in the oil. This invention will produce a quiet oil bath regardless, but the bubbles will persist. However, the bubbles cannot pass the top screen baflle to enter the air line.
Referring now to FEGURE 3, an alternate structure of an orientation member 50 is shown. In this embodiment, the structure includes an imperforate disc 51A which is at an angle with the head 11 of the tank 10. Normally, the duct leading into each tank is an elbow form in order that the lines may be attached to a side surface of the head. Because of this construction, the fluid has a strong propensity to flow along the designated flow lines C and thus favor one side of the tank. Hence,
there is more fluid flowing in this side of the tank and more tendency toward turbulance here. Therefore, to prevent flow to one side and to promote a uniform 360 distribution to the screen areas, the disc 51A is positioned at an angle with the end of the tank such that the end of the disc, at the side of the tank having the greatest fluid flow, is closer to the head llil.
Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
What is claimed is:
1. In a cycling oil and air system for operating a power cylinder the combination of, a tank having an opening at one end thereof, a hydraulic motor containing a supply of hydraulic fluid, means connecting the opening to said hydraulic motor and the contained supply of hydraulic fluid, said opening alternately serving as an inlet and an outlet, an orientation member carried by said tank and closely spaced from said opening, said orientation member having an imperforate central portion spanning and surrounding said opening, said orientation member having an outer portion, said outer portion including means to produce quiescent flow in individual stream substantially paralleling the axis of the tank when oil is introduced into the tank through said opening.
2. In a cycling oil and air system for operating a power cylinder the combination of, a tank having an oil port at one end thereof, a hydraulic motor containing a supply of hydraulic fluid, means connecting the port to the hydraulic motor and the contained supply of hydraulic fluid, said port alternately serving as an oil inlet and an outlet, an orientation member carried by said tank, said orientation member having an imperforate central portion spanning and surrounding said oil port, said orientation member having an annular outer portion extending beyond said central portion substantially to the walls of said tank, said outer portion including a plurality of spaced openings providing means to produce individual streams substantially paralleling the axis of the tank.
3. In a cycling oil and air system for operating a power cylinder the combination of, a tank having an oil port at one end thereof, a hydraulic motor containing a supply of hydraulic fluid, means connecting the port to the hydraulic motor and the contained supply of hydraulic fluid, said port serving alternately as an oil inlet and an outlet, an orientation member carried by said tank and closely spaced from said port, said orientation member having an imperforate central portion positioned to span and surround said port, an annular perforate outer portion extending beyond said central portion substantially to the walls of said tank, said central portion being generally flat and positioned normal to the axis of said tank walls, a perforate longitudinal screen extending substantially from the imperforate central portion toward the end of the tank :having the port opening, whereby, when oil enters said port, said oil will flow through the longitudinal screen and thence through the perforate baffie extension portion to separate the oil into individual streams generally paralleling the axis of the tank.
4. An air over oil device, the combination of:
(a) an elongated tank for vertical orientation;
(b) said tank including a tubular side Wall and end portions each including end walls closing the ends of the side wall, each portion including a port;
(c) an orientation member including an imperforate portion disposed across one of said ports and of a lateral dimension in all directions greater than the diameter of said one port, said imperforate portion being spaced from the side wall;
(d) means maintaining said orientation imperforate portion across said one port and in spaced relationship therewith whereby to divert laterally, the flow of fluid entering the tank from said one port;
(e) said member also including annular perforate screen baifie means extending from the imperforate portion substantially to one of the walls to separate fluid flowing into the tank into individual, substantially lineal streams and thereby provide quiescent flow; and,
(f) a hydraulic motor containing a supply of hydraulic fluid, hydraulic supply and return means connected to said one port and to said hydraulic motor and the supply of fluid contained therein.
5 5. The device of claim 4 wherein the imperforate portion is canted with respect to the axis of the port.
6. The device of claim 4 wherein the imperforate portion is a disc.
7. The device of claim 6 wherein the imperforate por- 10 tion is canted with respect to the axis of the port.
8. The device of claim 6 wherein the imperforate portion is perpendicular to the axis of the port.
9. An air over oil device comprising,
(a) an elongated tank for vertical orientation;
(b) said tank including Walls defining a tube and portions closing the ends of the tube, each portion having a port;
(0) an orientation member including an imperforate portion across one of said ports and spaced from the walls of the tube to provide an annular space therebetween; said imperforate portion having a diameter greater than the diameter of said one port;
(d) means maintaining said imperforate portion across said one port and in spaced relationship therewith whereby to divert laterally, the flow or" fluid entering the tank from said one port;
(e) said member also including a lateral perforate screen bafiie means surrounding the imperforate portion to substantially extend from said imperforate portion to said walls such that the member portion and means together form a lateral Wall;
(f) an annular screen bafiie means extending from said lateral wall to the end portion having said one port;
(g) said annular screen baflie means surrounding said port; and,
(h) said lateral and said annular screen baffle means sequentially and repetitively separating fluid flowing into said tank into individual streams whereby the fluid is repetitively screened.
10. The device of claim 9 wherein the annular baflie is U shaped in cross-section with one arm of the U of a diameter less than the member and the other arm of a greater diameter.
11. The device of claim 59 wherein the annular screen baffle means includes an annulus in the form of a U-shaped trough having:
(a) an apex abutting said end portion;
(b) an inner annular part extending axially to the imperforate portion; and,
(c) an outer annular part extending to the lateral screen bafiie means.
12. An air over oil device comprising,
(-a) an elongated tank for vertical orientation;
(b) said tank including walls defining a tube and first and second portions closing the ends of the tube, each portion including a port;
(c) first and second orientation members including imperforate portions disposed respectively across the across the first and second ports and each of a lateral dimension in all directions greater than the diameter of its port, each of said imperforate portions being spaced from the walls of the tube;
(d) means maintaining each of said imperforate portions across its port and in spaced relationship therewith whereby to divert the flow of fluid entering the tank from either port laterally; and,
(e) said members including first and second perforate baffle means extending in all directions from the imperforate portions of the first and second members respectively substantially to the walls defining the tube for separating fluid entering the tank into individual streams substantially paralleling the axis of the tank.
13. In a cycling liquid and gas system, the combination of:
(a) a hydraulic motor containing a supply of hydraulic fluid;
(b) a tank having spaced gas and hydraulic openings therein, gas and hydraulic supply and return means respectively connected to the gas and hydraulic openings;
(c) said hydraulic supply and return means being connected to the hydraulic motor and the contained supply of hydraulic fluid; I
(d) an orientation member carried by the tank, said orientation member including an imperforate central portion positioned to span and surround said hydraulic opening, said orientation member central portion being a means to baffle the flow; and,
(e) said orientation member including means to sequentially and repetitively screen fluid to produce quiescent flow of the fluid When the fluid is introduced into said tank through said hydraulic opening.
References Cited by the Examiner UNITED STATES PATENTS 354,730 12/86 Newton 55465 X 798,187 8/05 Keelin 55464 X 919,611 4/09 Martin 55462 X 1,337,564 4/20 Orem 55462 X 1,389,101 8/21 Ohrvall. 1,619,003 3/27 Steere 60- 51 X 1,684,834 9/28 Larsen. 1,892,210 12/32 Gordon 55492 2,242,278 5/41 Yonkers. 2,412,841 12/46 Spangler. 2,653,676 9/53 Breckheimer 137255 2,683,463 7/54 Flick. 2,818,937 1/58 Brixius. 3,053,233 9/62 Mead 55203 X REUBEN FRIEDMAN, Primary Examiner.
HARRY B. THORNTON, HERBERT L. MARTIN,
\VESLEY S. COLE, Examiners.