US3480146A - Hydraulic reservoir - Google Patents

Description

, Nov. 25, 1969. P. BARKER, JR 3,430,146

HYDRAULIC RESERVOIR Filed July 25, 1967 2 Sheets-Sheet 1 pierce E WK J" 2i JJ W Yak-1M I 35 GRTTQRNQYJ NOV. 25, 1969 R, JR 3,480,146

HYDRAULIC RESERVOIR Filed July 25, 1967 2 Sheets-Sheet 2 d "we FUOEY-f United States Patent US. Cl. 210250 8 Claims ABSTRACT OF THE DISCLOSURE A reservoir for storing hydraulic oil and including an upright hollow leg which supports the reservoir and also serves as a return conduit for oil flowing from hydraulic operating devices back into the reservoir. The leg is formed with an outlet spaced below and angularly offset from an inlet so that oilpassing through the leg from the inlet to the outlet must flow in a multi-directional path and, since heavy foreign particles carried by the oil resist such directional changes because of their high inertia, the particles are separated from the oil and settle to the bottom of the leg. A flow-directing baffle extends lengthwise within the reservoir and interconnects two end covers to enable removal of the covers by the release of a single screw.

BACKGROUND OF THE INVENTION This invention relates to a reservoir for use in a hydraulic system of the type in which hydraulic pressure fluid withdrawn from the reservoir by a power-driven pump is delivered first to a fluid-actuated operating device and then is returned to the reservoir for recirculation through the system. The reservoir usually comprises a tank having an outlet connected to the suction side of the pump and having an inlet communicating with a return line leading from the operating device.

SUMMARY OF THE INVENTION In its primary aspect, the present invention contemplates a new and improved reservoir of the above character which elfectively separates relatively heavy foreign particles from the pressure fluid Without the use of filters and traps the particles in a location remote from=the flow path and which, at the same time, may be cleaned more easily to remove foreign material from the system than prior reservoirs of the same general type. To achieve these ends, the tank is supported on a frame including an upright hollow leg which also serves as a return conduit leading into the inlet of the tank. The flow path through the leg from the return line of the operating device to the inlet of the tank is fashioned to cause the heavier foreign particles trapped in the fluid to settle to the bottom of the leg where a drain is provided to permit periodical removal of the particles from the system.

The invention also resides in an improved flow-directing baflie extending lengthwise of the tank and connecting a pair of end covers to the tank in a novel manner enabling quick and easy removal of the covers and convenient access to the interior of the tank.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a perspective view of a new and improved reservoir embodying the features of the present invention and installed in a typical hydraulic system.

FIG. 2 is a fragmentary plan view of the reservoir shown in FIG. 1 with parts being broken away and shown in section.

FIG. 3 is a fragmentary cross-section taken substantially along the line 3-3 of FIG. 2.

FIG. 4 is a perspective view of the hollow leg.

FIG. 5 is a perspective view of the bafiie.

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DETAILED DESCRIPTION As shown in the drawings for purposes of illustration, the invention is embodied with a reservoir 10 installed in a hydraulic system for storing a supply of hydraulic oil which first is drawn from the reservoir by a pump 11 driven by a motor 13 and then is returned to the reservoir after being fed to one or more fluid-actuated operatin devices (not shown) such as hydraulic rams or rotary fluid motors. The pump communicates with the outlet of the reservoir through a pipe 14 and a filter 15 connected to the suction side of the pump, delivers the oil to the operating devices through a supply line 16 communicating with the outlet of the pump, and returns the oil back to the reservoir through a set of return lines 17 to 20 connected between the operating devices and the inlet of the reservoir.

Herein, the reservoir 10 is formed as a cylindrical tank 21 which is closed at its ends by a pair of removable dishshaped end covers 23 and 24. The reservoir is cradled within a frame 25 comprising four upright corner legs 26 to 29 interconnected by a series of braces 30 extending longitudinally and transversely between the legs. Spanning the two upper transverse braces 30 is a horizontal platform 31 supporting the pump 11 and the motor 13 above the tank and adapted to be adjusted relative to the frame so that the motor and the pump may be set in a precisely leveled position for optimum operation. The platform may be leveled preliminarily by adjusting a first set of screws 32 threaded through the ends of the platform and bearing against the upper cross braces 30 thereby to raise or lower the ends of the platform to approximately the same height. A fine adjustment then may be made to position the platform in a horizontal plane by tightening a pair of adjusting screws 34 threaded through the central portion of the platform and acting against a crossmember 35 fastened to the upper side of the tank.

As the hydraulic oil is circulated from the reservoir 10 to the operating devices and back, small metallic chips and other foreign material are picked up by the oil and tend to accumulate in the reservoir. In accordance with the primary aspect of the present invention, the frame leg 26 is utilized in a novel manner not only to support the reservoir, but also to separate the foreign material from the oil and to trap the material in a location where it may be removed quickly and easily from the system. To these ends, the leg 26 is formed as a hollow enclosure which serves as a return conduit leading to the inlet of the reservoir. Oil returning from the operating devices flows through the leg and into the reservoir in a multi-directional path such that the heavier foreign particles carried by the oil, having a tendency to travel in a straight path as a result of their relatively high inertia, are separated from the oil and settle to the bottom of the leg where they may be removed periodically.

In the present instance, the supporting leg 26 is rectangular in cross section and is formed by four upright walls 37 to 40 joined together along their side margins to define a hollow enclosure. The lower end of the leg is closed by a rectangular base plate 41 welded to the lower ends of the walls, and the upper end of the leg is closed by a cover plate 43 welded to the upper ends of the walls. As shown most clearly in FIGS. 1 and 4, a section of the metal of the cylindrical tank 21 is cut away to form a relatively long slot 44 arcuately curved about the axis of the tank and of a width corresponding to the width of the inner wall 40 of the leg 26. The leg is fitted into the slot with the arcuate edges of the slot embracing the front and rear walls of the leg so that a portion of the inner wall corresponding in height to the height of the slot is disposed within the interior of the tank. To secure the leg to the reservoir and to establish a fluidtight seal between the leg and the tank, the arcuate edges of the slot are welded to the front and rear walls 37 and 39- and the top and bottom edges of the slot are welded to the inner wall 40.

Preferably, the return lines 18 to 20 leading from the operating devices are connected to a hollow manifold 45 (FIG. 3) of rectangular cross-section extending lengthwise of the tank 21 between the supporting legs 26 and 29. At its forward end, the manifold is fitted into a rectangular inlet hole 46 (FIG. 4) cut through the rear wall 39 of the leg 26 in the upper portion of the rear wall disposed outwardly of the tank. Accordingly,.oil flowing from the return lines passes through the manifold 45 and into the leg 26 through the inlet 46. From the inlet, the oil is returned to the reservoir through a rectangular hole 47 (FIGS. 3 and 4) cut through the inner wall 40 of the leg 26 in the portion of the inner wall disposed within the interior of the tank. The hole 47 is spaced below the inlet 46 and constitutes both the outlet for the leg and the inlet for the reservoir.

Since the outlet 47 is spaced below the inlet 46 and is disposed perpendicular to inlet, oil flowing forwardly from the manifold 45 must, in effect, change directions twice in passing through the leg 26 and flowing into the reservoir through the outlet 47. That is, the oil first must flow downwardly from the inlet 46 to the level of the outlet 47 and then must turn inwardly to pass through the outlet and into the reservoir. Any metal chips and other relatively heavy foreign particles entrapped in the oil are resistant to such directional changes, however,

because of their relatively high inertia and thus tend to continue to move in a downward path toward the bottom of the leg. As a result, a large quantity of the foreign material is separated from the flowing oil and settles in the lower portion of the leg away from active fiow path of the circulating fluid.

As shown in FIGS. 1 and 3, the return line 17 also communicates with the reservoir through the supporting leg 26, but this line is connected to a port 49 (FIG. 4) formed through the cover plate 43 closing the top of the leg. Like the oil flowing through the manifold 45, oil flowing downwardly from the return line 17 into the leg 26 through the port 49 turns inwardly to pass through the outlet 47 while the heavier foreign particles continue in their initial downward path and are separated from the oil. The trapped foreign particles in the lower portion of the leg may be removed from the system from time to time through a short drain pipe 50 fitted into a hole 51 in the lower end portion of the inner wall 40 and normally closed by a cap 53 which may be removed to open the drain.

Herein, the supporting leg 27 also is constructed as a hollow enclosure and is employed as the outlet of the reservoir 10 so that the oil flowing out of the reservoir will be subjected to a further separating action before being sucked into the pump 11 thereby to remove smaller foreign particles which may have remained in the oil. The leg 27 is substantially identical to the leg 26 and the parts thereof are indicated by the same but primed reference numerals. As shown in FIGS. 1 and 3, the suction pipe 14 communicates with the leg 27 through the top cover plate 43' and thus, as the oil is drawn into the pipe through the hole 47, small particles in the oil can settle in the lower portion of the leg 27 where they can be removed through the drain 50'.

In another of its aspects, the present invention contemplates a new and improved flow-directing baffie 55 extending lengthwise within the tank 21 and interconnecting the end covers 23 and 24 together in a novel manner such that both end covers may be removed from the tank to gain access to the interior of the reservoir by loosening a single threaded connection 56. Once the connection has been loosened, the end cover 24 simply may be pulled away from the rear end of the tank while the end cover 23 may be removed by pulling the baflle out of the forward end of the tank.

Herein, the baffle is positioned on the longitudinal center line of the tank'21 and extends vertically from the top to the bottom of the tank thus dividing the chamber of the reservoir into two sections. The forward end 57 of the baflle is curved in accordance with the curvature of the forward end cover 23 and abuts against and is welded rigidly to the inner face of the cover to establish a fluid-tight seal between the cover and the forward end of the tank. At its rear end, a corner 59 (FIG. 5) of the bafl le is cut away to form a passage between the two sections of the reservoir chamber. Accordingly, to pass from the tank inlet 46 to the tank outlet 47', the oil first must flow rearwardly along the left side (FIG. 3) of the baffle, turn through the passage formed by the cut-away corner 59, and then flow forwardly or reversely along the entire length of the right side of the baflle to the outlet 47'. The oil thus does notflow directly from the inlet 46 to the outlet 46', but instead, is deflected through a long multi-directional path between the inlet and the outlet to give the foreign material an opportunity to settle to the bottom of the reservoir.

To hold the end covers 23 and 24 on the tank 21 and also to permit easy removal of the covers, the threaded connection 56 comprises a screw extending forwardly through the center of the rear end cover 24 and threaded into a boss 60 formed on the rear end of the bafiie 55. When the screw is tightened, the end cover 24 is forced forwardly into sealing relation with the rear end of the tank and, at the same time, the baflle 55 is drawn rearwardly to clamp the rigidly attached forward cover 23 into tight engagement with the forward end of the tank. Both end covers may be removed to enable convenient access to the inside of the body for cleaning purposes simply by unthreading the single screw 56, pulling the end cover 24 away from the rear end of the tank, and then pulling the end cover 23 forwardly to remove this cover andto slide the baflle out of the tank. With this arrangement, both the baffle and the two end covers may be removed to expose the inside of the tank completely merely by releasing a single screw. To facilitate endwise sliding of the baffle into and out of the tank, a series of longitudinally spaced guide clips 63 (FIG. 3) are bolted to the upper and lower walls of the tank and are formed with U-shaped channels disposed within the chamber and embracing the upper and lower edges of the baflle. The clips also help to hold the bafile in an upright position within the tank.

Preferably, the baffle 55 is formed in two parts by a pair of separate plates 66 and 67 whose adjacent ends overlap each other and are fastened together by vertically spaced bolts 69. Thus, if the forward end of the reservoir 10 should be confined by surrounding structure in such a manner that the forward end cover 23 cannot be removed, unobstructed access to the rear half of the inside of the tank 21 may be gained by releasing the end cover 24 and the bolts 69 and by pulling the rear baflle plate 67 out of the tank. The rear half of the tank then can be cleaned without interference from the baflle plate 67, and implements for cleaning the forward end of the tank can be manipulated freely and without being obstructed by the rear baffle plate.

From the foregoing, it will be apparent that the use of the supporting leg 26 as a return conduit along with the novel arrangement of the inlets 46 and 49 and the outlet 47 enables separation of heavier foreign particles from the flowing oil without the need of filters. The battle 55 not only aidsin the separationo'f the foreign particles but also connects the two end covers 23 and 24 together in such a manner that the covers can be installed or removed with the use of only a single screw 56.

I claim as my invention:

1. In a reservoir for use with a hydraulic system ineluding a pump and a return line, the combination of,

upright hollow leg defining a return conduit, said leg having an inlet adapted to communicate with the return line of the system and having an outlet disposed below said inlet and communicating both with said inlet and with said chamber whereby fluid from the return line flows downwardly from said inlet to said outlet and into said chamber, said leg including a lower portion disposed below the level of said outlet whereby foreign material in the fluid flowing downwardly from the inlet to the outlet is induced to settle in said lower portion, a drain formed through one wall of said lower portion, and means normally closing said drain and selectively operable to open the drain to permit removal of the foreign material from the lower portion of said leg.

2. A reservoir as defined in claim 1 in which said inlet and outlet are formed in upright walls of said leg, said inlet being disposed above and being angularly spaced from said outlet whereby the fluid changes directions twice in flowing from the inlet to the outlet.

3. A reservoir as defined in claim 2 in which said leg is rectangular in cross-section with said outlet being formed in the wall facing said tank and with said inlet being formed in an adjacent wall.

4. A reservoir as defined in claim 1 in which said frame includes a second upright and hollow leg defining a supply conduit, said second leg having an inlet communicating with said chamber and having an outlet adapted to communicate with the pump, a second drain formed through one wall of said second leg below the level of the outlet and the inlet therein, and means normally closing said second drain and selectively operable to open the drain.

5. A reservoir as defined in claim 1 in which said tank is circular in cross-section and includes a cylindrical wall formed with a slot arcuately curved about the axis of the tank, a portion of said leg fitting Within said slot with the arcuate edges of the slot embracing the leg and with said outlet being disposed inwardly of said slot and communicating directly with said chamber.

6. In a reservoir for use with a hydraulic system including a pump and a return line, the combination of, an enclosed tank defining a chamber for storing hydraulic fluid, a frame supporting said tank and including an upright hollow leg defining a return conduit, said leg having an inlet adapted to communicate with the return 45 line of the system and having an outlet communicating both with said inlet and with said chamber, said outlet being disposed below and spaced angularly from said inlet whereby fluid flowing in a predetermined path to said inlet must proceed downwardly and then laterally of said path to flow from the inlet to said outlet and into said chamber, and said leg including a lower portion disposed below the level of said inlet and said outlet for collecting foreign material separated from the fluid as the latter flows through said leg.

7. In a reservoir, the combination of, a tank adapted to hold hydraulic fluid and having an inlet and an outlet, said tank having oppositely facing Open ends, a cover for closing each open end of the tank, a baffle extending lengthwise within said tank between said inlet and said outlet and fastened rigidly at one end to the inner side of one of said covers, and a threaded connection between the opposite end of said baffle and the other of said covers, said connection being movable to a tightened position to draw both of said covers into sealing relationship with the ends of said tank and being releasable to permit removal of both of said covers from the ends of the tank, said baffie being divided into a first section connected to said one cover and a second section connected to the other of said covers, and means fastening adjacent ends of said sections together releasably thereby to permit removal of said second section from said tank independently of said first section.

8. A reservoir as defined in claim 7 further including means within said tank guiding said baflle for endwise sliding in the tank.

References Cited UNITED STATES PATENTS 1,407,936 2/1922 Crosby 2l0533 X 2,284,413 5/1942 Frentzel 210-533 2,375,590 5/1945 Schonberg et al 210-521 2,498,292 2/1950 Naugle 210521 2,745,510 5/1956 Hultgren 210-532 3,037,634 6/1962 Mills 210-232 X REUBEN FRIEDMAN, Primary Examiner JOHN W. ADEE, Assistant Examiner U.S. Cl. X.R. 2l0536

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