US1366138A - Rotary pump and similar apparatus - Google Patents

Description

w. F. TRAUM'. ROTARY PUMPAND SIMILAR APPARATUS.

- APPLICATION FILED AFR. 22| 1919. 1,366,138.` Patented Jan. 18, 1921.

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ROTARY PUM'P AND SIMILAR APPARATUS. APPLICATION msn Amzz. |919.

I 1,366,138'. Patented Jan. 18, 1921.

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WILLIAM F. TRAUDT, OF BUFFALO, NEW YORK, ASSIGNOB TO. TABER PUMP COMPANY, A CORPORATION `Olli' NEW YORK.

ROTARY PUMP AND SIMILAR APPARATUS.

Specification of Letters Patent.

Application 'led April 22, 1919. Serial N0. 291,929.

To all 'whom t 'may concern.'

Be it known that I, WILLIAM F. TRAUDT, a citizen of the-United States of America,

residin at Buffalo, lcounty of Erie, State of' New ork, have invented certain new and useful Improvements'in Rotary Pum s and Similar Apparatus, of which the fol owing is a specication.

My invention relates generally. to that class of mechanism used for rotary pumps or rotary engines, and more specifically it nds its' most successful application to that form of engine or pump which has a cylindrical rotor mounted eccentrically in a cy lindrical casing so as to touch the casing along a common element Vof the two cylindrical surfaces between the inlet and outlet ports of the casing, and which rotor has two or more radial pockets each of which has a bucket mounted and movable therein so as to lkeep always in contact with the casing wa I have illustrated my invention as applied to a pump but it is obvious that if iiuld under pressure were supplied to the port which is the outlet of the pump and allowed to escape from the port which serves as the inlet to the pump, the apparatus would then function as a rotary engine or motor.

Heretofore when apparatus of this kind has been used for eit er purpcse, the main dihficulty has been the slip7 or loss of fluid which passed by the buckets. In pumps of with in the use of vthis type of mechanism are overcome by my invention almost completely. i

The best form of apparatus embodying iny invention at present known to me is illustrated in the accompanying two sheets of drawings in whichi y,

Figure l is a vertical section ofa pump taken on line l-l of Fig. 2.

Fig. 2 is an axial, vertical section of the Pump' .Fi 3 1s a similar vlew showing a modified orm of bucket. Fig. 4 is a perspective view of such bucket on an enlarged scale, and

.in their pressure faces Fig. 5 is a similar perspective view of the packlng strip used therewith.

Throughout the -drawings like reference characters indicate like parts.- l, is a cylindrical casing mounted on a suitable base and having an lnlet 2, and an outlet 3, spaced apart circumferentially and preferably at 180 de ees. 4, is the usual rotor mounted eccentrlcally of the casing on shaft 7 and in contact with the casing wall along a common element of the two cylinders at a point 24:, midway between the inlet and outlet ports. 5, 5, are buckets, preferably four in Patented Jan. 1S, 1921.

number as shown, mounted-and sliding in radial pockets 26, 26, in the rotor which are 'is forced outwardly and against the casing walls by springs 1l, l1, compressed between them. These springs are cased in tubes 12, 12, which pass diametrically through rotor and shaft, itting'tightly in the former but movable therein. 22, 22, are sockets in the inner edges of the buckets for receivingthe ends of tubes 12,112. 10, 10, are passages in the buckets leading from their inner edges, located in the rotor pockets, to points i. e. the faces eX-' posed to pressure of t eV liquid passing through the apparatus, whether used as a pump or as an engine) which are exposed during the period while the bucket is passing from the inlet tothe outlet port. In Fig.' l, the rotor revolves clockwise, as indicated by the arrow, when the apparatus is used as a pump. It would revolve counterclockwise if the apparatus were used as a motor.

In the modification shown in Fig. 3, the tubes 12, are provided Awith cross partitions 13, located approximately midwayY of the length of each tube. In this construction there is a shorter spring 16, on each .side of said partition instead of one long spring 1l, going all the way through the tube' as in the construction shown iny Fig. 2. The tubes also pass through little stuing boxes 14, 14. mounted in the rotor. This construction reduces to a minimum any leakage of fluid through or around the tubes.

In this modification one end of each bucket is provided with a packing strip 15. having ya longitudinally extending tongue 17, adapted to engage a groove 18, running along the end of the bucket. Packing strip and bucket are forced apart by springs 21. 21, mounted in sockets in each. and these parts may be guided by pins 25, 25. The bucket has a cross slot 19, deeper than slot or groove 18, and the packing strip has a cross tongue 20, longer than tongue 17, and registering with cross slot 19.

In operation, 'the lluid being pumped or used to drive the apparatus as a motor, gets between the outer edge of each bucket and the casing wall while under pressure, z'. e. during its transportation by the pump rotor and bucket from inlet port to outlet port. Whenever this pressure is considerable and not counterbalanced it will overpower springs 11, or 16, and the fluid will escape to the other side of the bucket. The buckets then jump in and out with a loud chattering soundl and much slip or leakage occurs. lf the springs are made strong enough to prevent this the wear and tear and loss of power through internal friction become prohibitive. Efforts have been made. to overcome this diiiculty by admitting the fluid yunder pressure to the bottom of the bucket pockets, but in prior apparatus where this has been done the mistake has been made of dispensing with the springs and relying on thepressure alone, or on centrifugal force, to hold the buckets out and up to the work. But as the pressure on the two edges of the bucket are of course approximately equal. thereis not suflcient preponderance of the outward thrust of the liuld, if any, to hold the bucket against the casing, and centrifugal force varies with the speed of revolution. so that until the pump reaches a certain speed of revolution the friction of the bucket Nin its pocket and its inertia are not overcome. Consequently the bucket does not move out to contact with the casing wall andthe slip, or leakage, is large until the pump reaches a high speed of revolution.

In my invention the pressures on the inner and otter edges of each bucket are equalized by the flow of liquid throu h the bucket passages 10, 10, or through t e rotor passages 23, either or both, and so the springs 11, or 16, which are given just the right force to secure a tight joint between bucket and casing, are left free to exert their entire thrust for this purpose. As a result the most perfect conditions obtainable and originally created by proper design are maintained at all times.

The advantage of having the bucket springs go through the rotor is that then the small relative movement between the two buckets of each pair is all that the iexing of the springs has to take care of, the springs and their incasing tubes and the buckets moving back and forth nearly through the same distances and together, diametrically of the rotor. The" disadvantage of the ordinary arrangement of this type is leakage or slip of fluid through and around the tubes. from the pressure side of the pump to the suction side. This is eliminated in my invention by the cross partitions 13, in the tubes, and stuiing boxes 14, making tight joints with the rotor around he tubes.

The spring controlled packing strip 15, is designed, of course, to take up' end wear of the casing and buckets and so to prevent leaka e and slip at the ends of the buckets, but w en the tongue 17, is partly withdrawn from groove 18, as the strip moves 'out after wearing down, there are passages formed between strip and bucket leading from the rotor pocket out to the suction side of the bucket beyond the rotor, through which passages leakage will occur. The cross tongue 20. employed in my invention, reaches across these passages into cross slot 19, and blocks olf this leakage.

With these reinements a rotary pump can be used to handle asolene and other iuids of low viscosity with the highest degree of eiciency.

The diagonal bars or strips across the pump ports equalize the wear on the entire outer edge of each bucket. Without these a portion of each bucket edge opposite the port is relieved from wear whilel passing such port, and the excess wear then resulting near the extremities of the bucket edge or lip soon produces depressions there which create leakage spaces while the bucket is travelin between ports.

The simple form of pump shown in Figs. 1 and 2, has been run with water against a head of pounds with only 16 per cent. slip, while the same pump with the pressure equalizingY passages 10, plugged up gave 80 per cent. slip when worklng against the saine head.

Having described my invention, I claim:

1. In a rotary pump or similar structure the combination of a cylindrical casing provided with inlet and outlet ports spaced some distance apart circumferentially, a rotor journaled in said casing and provided with radial pockets, buckets mounted and adapted to slide in said pockets, comparatively weak springs holding said buckets outward against the cylindrical casing walls and means for equalizing the fluid pressure on the outer and inner edges of said buckets throughout the period of their travel from the inlet port to the outlet port.

2. In a rotary pump or similar structure the combination of a cylindrical casing provided with inlet and outlet ports spaced some distance apart circumferentially, a rotor journaled in said casing and provided with radial pockets, -buckets mounted and adapted to slide in said pockets provided with passages extending from their inner edges to points in their pressure faces exposed While traveling from inlet port to outlet ort, and comparatively Weak springs hol ing said buckets outward against the cylindrical casin walls.

3. combination such as set forth in claim 1 in which the means for equalizing pressures comprises passageways extending through the buckets from the inner edges thereof to points on the pressure faces thereof exposed during the period of travel from inlet to outlet port, and passages through the rotor.

4. In a rotary. pump or similar structure the combination of a cylindrical casing provided With inlet and outlet ports in its` cylindrical walls spaced some distance apart circumferentially, a rotor journaled in said casing and provided With radial pockets, buckets mounted and adaptedto slidev in said pockets, comparatively weak springs holding said buckets outward against the cylindrical casing Walls and means' for admitting to the bottom of each pocket, dur-l ing the entire period of its travel 'from in let to outlet port, some of the Huid which is passing from one port tothe other and pressing against a face of the bucket in that pocket.

5. In a rotary pump or similar'structure having a cylindrical casing, a rotor in said casing and sliding buckets mounted in the rotor, the combination, with such bucketsl having longitudinally grooved ends, of pack ing strips having tongues tting into said grooves, and springs for forcing said packing strips outwardly, said bucket ends having cross grooves deeper than the longitudinal grooves and said packing strips having cross tongues registering with the cross grooves and. longer than the longitudinal tongues.

6. A slidin bucket for use in rotary pumps and'li e structures having a main body grooved longitudinally along one end and cross grooved to a greater depth, a packing strip having a longitudinal tongue fitting in the longitudinal groove in the bucket and a longer cross tongue fitting in the cross groove, and springs tending to force said packing strip away from the bucket body.

7. In a rotary pump or similar structure the combination of a cylindrical casin provided with inlet and outlet ports space some

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