US2200198A - Vacuum pump - Google Patents

Description

May 7, 1940. y 5155A@ n 2,200,198

VACUUM AUMP Filed Sept. 14, 1938 2 Sheets-Sheet 1 INVENTOR ffm E. J. BEAH VACUUM PUMP May 7, 1940.

2 Sheets-Sheet 2 Filed Sept. 14, 1938 wrrNEssEs k INVENTOR EdwardJBeach UZ- BY ,J

ATTORNEYS Patented `Mayn 7, 194() UNITED STATES 2,200,198 VACUUM rum Edward J. Beach, Brooklyn', N. Y., assgnor to Beach-Russ Company, New York, N. Y., a cor` poration of New York Application September 14, 1938, Serial No. 229,828 i 2 Claims.

This invention lrelates to vacuum pumps and particularly to anl improved rotary pump, an object being to provide a simple construction wherein a very high vacuum may be secured and 5 maintained. 4

Another object of the invention is to provide an improved rotary vacuum pump associated with an oil, water and air separator, the arrangement being such that ample lubrication is provided without the loss of oil.

A further object of the invention is to provide an improved rotary vacuum pump wherein a discharge from the pump operates through a-plurality of valves arranged in series.

In addition, a more speciiic object of the invention is to provide a rotary pump wherein a pair of hollow piston blades are arranged and. function as a single or integral structure with the parts so arranged that one side of the piston blades acts as a suction side and the other as a compression side.

In the accompanying drawings- Fig. 1 is a` longitudinal vertical sectional view through a pump and oil separator embodying the invention;

Fig. 2 is a sectional view through Fig. 1 approximately on the line 2 2;

Fig. 3 is a fragmentary sectional view through Fig. Z-approximately on the line 3 3;

Fig. 4 is a side elevation of a piston blade with its shim illustrating certain features of the invention; l

Fig. 5 is a fragmentary sectional view through Fig. 1 approximately on the line 5-5 and illustrating part of the valve structure; I.

Fig. 6 is an enlarged fragmentary view of part of the valve structure shown in Fig. 1.

Referring to the accompanying drawings by numerals, i indicates a vacuum pump which is associated with an oil separator tube andA with an outlet valve structure 3. It will benoted that air is drawn through the pipe 4 into the chamber l 5 of cylinder 6 and then is expelled through the valve structure. The parts are continually lubricated with oil by any desired oiling system and some of the oil is being continually dispelled so that the valve structure" 3 is provided with an oil level to a certain extent. Most of the air and oil, however', pass out through the outlet passageway 1 to the inlet pipe 8 of the oil separator tube. The oil separator tube is a well-known vdevice now on the market and forms no part of the present invention except in combination. The air, oil and any water condensation are discharged through 'pipe 8" into the chamber 9 of the sepa- (Cl. 23o-152) rator tube. The water, dirt and the'like will naturally drop down to the bottom while the oil floats andthe air will eventually pass out through the discharge pipe I0. The oil is used over and over .continuously and continually seals and lubricates the various parts of the pump'.

The pump may be used for 'any desired purpose. However, it is designed primarily to be used with devices which have some degree of Ararefaction whereby a high rarefaction may be secured if del0 sired. For instance, pipe 4 may be connected to a tank and this tank adapted to be maintained with a desired rarefaction by the continuous `operation of the pump. From the tank suitable pipes or hose members could extend to be used u in providing rarefaction for electric bulbs or for other purposes.

When used as just mentioned a certain amount of air will naturally enter the tank. By the continuous operation of the pump I this air entering m the suction tank will be quickly exhausted so that the degree of rarefaction will be maintained almost constant and this rarefaction .will be high because of the construction of the pump i which constantly tends `to create an almost perfect rare- 25 faction.

The chamber Eris preferably elliptical and has arranged therein a piston which consists of a rotor l2 and a. piston blade I3. v The blade I3 is formed preferably of two sections, namely, sec- 30 tion i3' and section i3". These sections are identical in construction so that a description of one will apply to both. As illustrated in Figs.

1, 2 and 4 it will be seen that there is provided a chamber- Ill in each section having outlets I5 as which are elongated as illustrated in Fig. l. Each section is also provided with an inlet passageway I6 adapted to register atuproper times with an arc-shaped inlet slot il formed in the`endy I8 of the cylinder 6. A plurality of sockets or bores vi!! 40 are providedin each'of the sections of the blade I3 and a pin 20 is provided for eachpair ofv-sockets or bores so that the sections may be properly aligned at all times. Each section is provided at the outer end withfan arc-shaped groove 2l in which a packing strip 22 ismounted. One sur- `face of this packing strip is curved on the same arc as the groove .and iits accurately therein. The other surface of the packing strip is curved 50 to the shape of the inner wall of the cylinder 6.

' As the piston operates the packing strip 22 will naturally oscillate slowly but will always maintain a tight connection between the piston blade and the cylinder. This is particularly true been cause of the lubricant providing a sealing medium at all parts over the surface of the strip 22.

.In course of time if the strip 22 should wear, a shim 23 may be used as illustrated particularly in Fig. 4. This shim may be ve thousandths of an inch thick, 0r, if desired, thicker or thinner but sufficient to take up the wear and cause the packing strip 22 to"properly engage the inner wall of the cylinder 6. In case further wear is produced at a later date the rst shim may be taken-out and a thicker one applied or, if preferred, two thinvones may be used. In case of excessive wear it will naturally be.` necessary to provide new packing strips 22 though for ordinary use these strips will last for a very long time and function accurately to provide a tight connection so that a high rarefaction or vacuum may be maintained in thef tank or other device to which the pump is connected. f

As shown inA Fig. 2, the cylinder 6 has a permanent head or end 24 and a false head or end 25.A A chamber or space 26 is arranged between these two heads and this space is usually maintained substantially lled with oil. This construction is desirable as the floating head or disk 25 provides an automatic by-pass that is usefulunder certain circumstances. ll'or instance, when the pipe is connected with a tank lled with air at atmospheric pressureand the pump started, the pressure on the outlet side of the pump will be appreciably higher than the atmosphere and, consequently, what air does not escape through the outlet valve structure 3 will press against the disk 25 and move the same longitudinally of the cylinder 6 and allow the air to by-pass or leap past the ends of the sections I3' and I3". will allow the pump to worky in an easy manner when working under atmospheric pressure. 4As, the tank or. other device begins to be evacuated the atmospheric pressure acting in the space will cause the false head or disk 25 to rest firmly against the shoulders 21. This will result in the pump functioning in the desired manner to quickly raise the rarefaction in the tank to a high point and to maintain the same at a high point. When the pump is functioning fully and normally l there is a comparatively small amount of air drawn in and, consequently, a comparatively small amount of air discharged through the valve structure 3. This will readily be evident when it is realized that the tank being maintained evacuated has already a rather high rarefaction.

In case all. outlets to the tank were closed the pump would continue to function to secure the highest possible vacuum in the tank and would then rotate freely as it wouldbe functioning in an almost perfect vacuum. As soon as air was admitted into the Atank the strain on the pump would vbegin and increase in proportion to the amount of air admitted to the tank.

As shown in Fig. 3, a screen 28 is vprovided in the tting 23 to which the pipe 4 isconnected. In this way all air .entering the pump must pass through the screen 28 which will exclude most, if not all, of the dirt. 'Ihe tting 29 is provided with a hollow enlargement 36 which iits over the inlet opening I1. l

'I'he rotor I2 is provided with a closed end 3l, as shown in Fig. 2 said closed end having openings 32 and 33 which are positioned to register with an opening I1 at different times, as illustrated more particularly in Figs. 1 and 2. when the parts are positioned as shown in Fig. 1, nie opening I6 of section I3' will be in register with opening I1 but vwhen the piston makes a hall' This revolution the opening I6 of section I3" will-be in register with the arc-shapedopening I 1 and the opening I6 in section I3' will be out of register. Therefore, it will beseen that during what may be termed the suction stroke of either section that particular section will have its opening I6 in registry with the opening I1 but during its compression stroke its opening I6will be out of register with the arc-shaped opening I1.

The outlet valve 3 is arranged at one side of the cylinder 6 and includes a casing 34 which is bolted to suitable projections 35 and 36 preferably' desired number of passageways 45 which register with a similar number of passageways 46 in the cylinder 6. The passageway 46 may be a single slot or a row of holes to form an outlet for the cylinder 6, said outlet discharging into the passageway 45 which is preferably a slot and which discharges into the slot 41 of the valve plate 43. A valve head 48 is provided for the valve structure and is guided in its movement by a shaft or pin 49 whichloosely and slidingly ts in a socket 42. A spring 5I surrounds the pin 49 and presses around a shoulder 52 and against the head 48 for continually urging the head against its seat. A wafer head 53 is arranged between head, 48 and the valve plate 43. This is a very thin sheet of metal, as for instance anywhere` from two-thousandths or three-thousandths of an inch to ten-thousandths of an inch thick. This metal may be steel or other exible metal.

The bat hes or increments of air, oil and foreign mat er passing the valve structure are very small and by the use of the wafer head these increments readily pass and then the parts quickly reseat themselves. 'I'he increments just mentioned are discharged into a chamber 54 and suits in` providing an eillcient seal whereby a high vacuum may be quickly obtained. This valve head 56 is carried by a pin 51, which pin is normally pressed by a spring 58. Suitable passageways 59 are formed in the casing 4I adjacent the valve head 56 whereby oil and the like may readily escape into the chamber 38. Air. oil, and occasionally a small amount of water, are discharged intov chamber 38 and pass upwardly through the passageway 1 and pipe 8 into the oil separator where the separator retains. all the matter except the air which is allowed to escape. When the pump is rst started a considerable. volume of air is discha ed but as the vacuum increases less and less ir will be discharged. In Fig. 5 it will be seen that the pinsf53'- guide the wafer head or valve structure 53 as it moves upwardly anddownwardly. In Fig. 2 the shaft I2' indicates that power from any desired source may be applied to the rotor as this shaft is connected'readily to or formed integral with the rotor I2. During the normal functioning of the v'I claim:

1. In a. vacuum pump of the character described, ay casing, a piston f ormed with a rotor having a passageway extending therethrough positioned in said casing, a blade slidingly mounted in said passageway, a packing strip arranged at each end of the blade, said blade being divided centrally longitudinally thereof, means for holding the respective parts of the blade in alignl 10 ment, a removable shim positioned between said parts held in place by said means and functioning to hold the parts of said blades so that said packing strips will continually engage said casing, each of said parts having an inlet, a chamber and a plurality of outlets, the outlets at one end portion of the blade facing in the'opposite direction to the outlets at the otherend portion.

2. In a vacuum pump of the character described, a cylinder having a chamber provided with an arc-shaped inlet opening at one end near the center of the end and an outlet opening in one side and a piston arrangement in said cylinder having a rotor eccentrically mounted in the cylinder so as to continually contact with the side wall of the chamber adjacent said outlet and normally cover said outlet, a piston blade slidingly mounted in said rotor formed with rockable means at each end engaging the walls of the cylinder,` said piston being divided into two parts, a removable shim for adjusting the position of the parts to maintain 'the respective outer edges of the piston in engagement with the side walls of the cylinder, each of said partsy having a chamber, an inlet opening and an outlet opening, the outletopening of one part facing in the opposite direction to the outlet opening of the other part, the inlet openings of the respective parts being 'so designed that when one of the parts passes over the arc-shaped inlet at the end of said cylinder the inlet opening of said 'part will register with said arc-shaped opening so as to draw air into the cylinder.

EDWARD J. BEACH.

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