US1972204A - Pump - Google Patents

Description

K. SCHOENE Sept. 4, 1934.

PUMP

Filed April 15. 1933 2 Sheets-Sheet 1 s 3 nnielntor w m m m Patented Sept. 4, 1934 PUMP Kurt Schoene, Hamburg, German,

Application April 15, 1933, Serial No. 666,384 In Germany April 26, 1932 18 Claimla (Cl. 103-203) This, invention relates to plungerpumps, and particularly to pumps of the type described and claimed in my prior Patent 1,760,172, May 2'7,

The pump of that prior patent is characterized by the use of inlet ports formed through the side walls of the cylinder and arranged to deliver the entering liquid against the pump plunger, which is given a special configuration designed to re:-

cover from the entering liquid at least a part of its kinetic energy.

The discharge valves are mounted in the head of the pump and are of conventional automatic type. The inlet port, however, is positively controlled, primarily by the encircling sleeve valve, and secondarily by the plunger itself.

In order to secure a satisfactory timing of the inlet flow for the recovery of energy, it is desirable that the inlet ports be located a considerable distance from the head end of the cylinder, and from this it follows that the plunger overtravels and completely closes the inlet ports in its motion to the head end dead point. Consequently when the plunger starts to leave the head end dead point, a partial vacuum is created, and the energy applied to the formation of such vacuum is not wholly recovered in other parts of the cycle. The object of this invention is to provide means.

which preclude, or at least reduce, the formation of the partial vacuum. These means take the form of a bypass controlled by a valve and functioning to admit liquid from the inlet ports to the working space at a time when the plunger has overtraveled and closed the inlet ports.

One advantage of the use of the bypass port is that motion of liquid in the inlet port toward the working space is initiated earlier in the suction stroke. In the preferred embodiment of the invention, the bypass port is formed in the plunger, and so arranged as to recover a portion of the kinetic energy of liquid entering the working space through the bypass.

The preferred embodiments of the invention are illustrated in the accompanying drawings, in which,--

Fig. 1 is a vertical axial section through the upper portion of the cylinder and plunger of the pump embodying the presentinvention.

Fig. 2 is a plan view of the plunger.

Fig. 3 is a fragmentary view showing the bypass ports formed in the plunger as in Figs. 1 and 2, but making use of valves of a difierent type.

Fig. 4'is a view similar to Fig. 1, showing a 55 modified embodiment of the invention, in which the bypass is formed in the cylinder head and cylinder,

Referring first to Figs. 1 and-2, the cylinder walls of the pump are shown at 6 and are encircled by a seat 7 for the reciprocating sleeve 90 valve 8 which exercises primary control over the inlet ports 9. The inlet ports 9 are arranged in circumferential series around the cylinder and are subject to secondary control by the plunger 11.

As set forth in my prior patent above identified,- the upper surface of the plunger 11 is specially formed to deflect liquid entering through the ports 9 on the suction stroke after the plunger has passed below these ports, the purpose being to recover kinetic energy from the entering liquid. To this end the plunger is provided with an upstanding conical projection 12.

The discharge valves, which are indicated at 13, are of the ring type, and coact with a slotted seat formed in the head casting 14 which is mounted on the cylinder. It is immaterial to the present invention whether the discharge valves 13 be provided with seating springs, and to simpiify the drawings, no attempt to illustrate such spring structure has been made.

It will be understood that the plunger 11 and the sleeve 8 are driven in proper timed relation by any suitable means, the simplest available being a single shaft carrying the crank which reciprocates the plunger 11, and two eccentrics which reciprocate the sleeve 8. The crank and the eccentrics are so angularly displaced from each other that after the plunger '11 has overtraveled the ports 9 in its upward motion and has closed the ports, the valve 8 moves downward and exposes the outer ends of the ports which are then closed by the plunger. The plunger continues upward to the dead point and on its downward suction stroke, tends to create a vacuum in the space above the plunger. By the time the plunger has moved'downward far enough to commence to expose the inlet ports 9, the sleeve 8 will have moved downward far enough to expose the outer ends of these ports completely or substantially so.

In order to prevent the plunger 11 from drawing a partial vacuum above it as it starts downward, the piston 11 is provided with a plurality of radial ports 15 which lead inward from its periphery and then curve upward, as indicated at 16; When the plunger 11 is at or near the head and dead point, the ports 15 communicate freely with the suction ports 9. The ports 15 discharge upwardly past an annular valve 17 overhanging ring 18. The ring 18 has a depend- .ing annular rib 19 which enters an annular slot in the top of the valve 17 and defines two flow paths 21 and 22, which take the form of annular slots (see Fig. 2). The slots 22 are interrupted by the sustaining bridges 23, clearly shown in Fig. 2, and visible at the left hand side of Fig. 1.

As soon as the plunger 11 starts downward and before the sleeve valve 8 has completely opened the ports 9, the passages 15, 16, offer 'a flow path upward through the piston, past the valve 17. There are several desirable results. The work of drawing the partial vacuum above the plunger is avoided. Inward flow is started throughthe ports 9, and some of the kinetic energy of such flow is recovered by the force reaction upon the plunger 11.

At all ordinary speeds no spring is necessary to seat the valve 17. At speeds so high that the inertia of the valve 17 would unseat the valve upon approach to the head end dead point, before the sleeve valve 8- opens the port 9, it may be found desirable to add springs to seat the valve, according to conventional practice, but in view of the extensive use of springs to seat annular valves, I do not regard such detail as involving patentable subject matter, and since springs are commonly unnecessary, and even undesirable, because of the resistance to flow, they are not illus trated in Figs. 1 and 2.

Referring to Fig. 3, a modified construction is shown, in connection with a plunger 111. Instead of using asingle annular valve 17, use is made of a plurality of poppet valves 117. 'ihese coact with seats 116 screwed into the outer ends of the ports, and are limited in their opening movement by cages 118 alsoscrewed into the outer ends of the ports. With this construction a loading spring 119 is considered necessary. since the valves 117 have not inherent seating tendency, such as that possessed by the valve 17, at the commencement of its upward stroke.

While only two valves appear in Fig. 3, it is to be understood that a circumferential series of closely spaced valves is used in order to get the maximum possible port capacity.

The interruption of the reaction surface on top of the plunger is more serious in connection with the structure of Fig. 3 than that encountered with the construction of Fig. 1, for the reason that in Fig. 1 the ring 18 substantially masks the bypass ports.

Where it is desired to avoid any interruption of the reaction surface on the head of the plunger,

, or where high speeds entail the use of larger tially identical inform with the parts numbered 6 to 14 in Figs. 1 and 2. Instead of the ports 15,

16, use is made of a plurality of ports 215 which lead from the ports 209 through the upper portion of the cylinder casting, and thence through passages 216 into the working space above the plunger 211..

' The ports 215 form an annular series spaced to correspond with the spacing of ports 209. The ports 215 are all controlled by a single annular valve 217, which is limited as to its lift by the overlying ring 218 held in place in a recessin the cylinder casting 206 by means of the head' casting 214. Ring 218 is held by bridges 223.50

which is centered and limited as to its lift by an that flow is permitted past both the edges of the ring. It carries guide fingers 219 which center the valve 217, and is provided with pockets 221 for coil compression springs 222, which urge the valve in a seating direction.

The operation of this valve is the same as that already described with reference to Figs. 1 and 2, except that there is, of course, no recovery of kinetic energy from liquid flowing through the ports 215. This structure presents the advantages that no partial vacuum is created by the plunger, and that the liquid in ports 209 is put in motion before the plunger exposes these ports. It can be used in structures which because of their size and high speed, will not permit satisfactory use of the constructions shown in Figs. 1 to 3 inclusive. Contributing causes are that the valve 217 is out of the path of flow through port 209 and may remain open so long as the resistance to flow through the valve 217 is less than the resistance ofiered by flow directly through the ports 209. In fact, it is not essential that the valve 217 close until near the end of the discharge stroke, so that there is ample time for closure. This permits the use of high lift and light spring loading. Consequently where the rotative speed of the pump is high, or the suction head is considerable, or where both these conditions exist,-the structure of Fig. 4 is considered peculiarly desirable.

In connection with the valve location shown in Fig. 4, it may be said that while I- prefer the use of a single valve 217, any valve mechanism which would control the ports 215, might be substituted, just as a plurality of valves are substituted in the structure of Fig. 3 for the single valve characteristic ofFig. 1. The specific form of the valve is not material to the broader aspects of the invention.

Generally stated, the invention is subject to various specifically different embodiments, and those disclosed above are to be considered as illustrative and not limiting.

What is claimed is, I

1. In a pump, the combination of a cylinder having an inlet port and a discharge port; an inlet valve controlling the inlet port; a discharge valve controlling the discharge port; a displacing plunger arranged to reciprocate in said cylinder and to overtravel and close said inlet port; abypass eilective when said plunger closes said inlet port, to connect the inlet port with the working space inthe cylinder; and a non-retum valve controlling flow in said bypass and permitti' flow toward said working space.

, 2. The combination defined in claim 1, in which the bypass .is formed in the cylinder.

3. The combination defined in claim 1, in which the bypass is in the form of a plurality of ports formed in the cylinder wall in a circular series, and the non-retum valve is a ring valve controlling such plurality of ports.

4. The combination defined in claim 1, in which the bypass takes the form of at least one, port formed in the plunger and arranged to register with the inlet port when the plunger has overtraveled such port.

5. The combination defined in claim 1, in which the bypass takes the form of .a plurality of ports formed in the plunger and arranged to register with the inlet port when the plunger has overtraveled such port, said ports in the plunger curving to discharge substantially in the direction of the axis of the plunger.

6. The combination defined in claim 1, in which the bypass takes the form of a plurality of ports formed in the plunger and arranged to register with the inlet port when the plunger has overtraveled such port, said ports, in the plunger curving to discharge substantially in the direction of the axis of the plunger, and the non-return valve is in the form of ,a ring valve, protected by an overlying guard ring and controlling all said ports.

7. In a pump, the combination of a cylinder having an inlet port and a discharge port; a mechanically actuated reciprocating inlet valve controlling the inlet port; a discharge valve controlling the discharge port; a displacing plunger arranged to reciprocate in said cylinder and to overtravel and close said inlet port, said plunger and inlet valve being so timed that the valve closes the inlet port on the discharge stroke of the plunger until the plunger has overtraveled such port, and thereafter starts to open the inlet port at least as early as the commencement of the suction stroke of the plunger; a bypass leading from a point in said inlet port intermediate said inlet valve and cylinder past said plunger to the working space in said cylinder, at least when the plunger has overtraveled said port; and a non-return valve permitting flow in said bypass toward such working space.

8. The combination defined in claim '7, which the bypass is formed in the cylinder.

9. The combination defined in claim '7, in which the inlet port encircles the cylinder and is controlled by an encircling sleeve valve.

10. The combination defined in claim 7, in which the inlet port encircles the cylinder and is controlled by an encircling sleeve valve, the bypass is in the form of a plurality of ports arranged in a circular series, and the non-return valve is of the ring type and controls the last-named series of ports.

11. The combination defined in claim '7, in which the inlet port encircles the cylinder and is controlled by an encircling sleeve valve, the bypass is in the form of a plurality of ports arranged in a circular series in the cylinder wall, and the non-return valve is of the ring type and controls the last-named series of ports.

12. The combination defined in claim '7, in which the bypass is in the form of a plurality of ports formed in the plunger and arranged to register with the inlet port when overtraveled by the plunger, said ports discharging through the end of the plunger approximately in the direction of the axis thereof.

13."The combination defined in claim 7 in.

inlet port; a discharge valve controlling the discharge port; a displacing plunger arranged to reciprocate in said cylinder and to overtravel and close said inlet port; a bypass effective when said plunger closes said inlet port to connect the inlet port with the working space in the cylinder, said bypass leading from a point beyond the inlet valve, whereby bypass flow is controlled by the inlet valve; and a non-return valve also controlling said bypass and limiting flow therein to a direction toward said working space.

15. The combination definedv in claim 1 4, in which the bypass is formed in the cylinder.

16. The combination defined in claim 14, in which the bypass takes the form of at least one port formed in the plunger and arranged to register with the inlet port when the plunger has overtraveled such port.

KURT SCHOENE.

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