US1909756A

US1909756A - Rotary pump

Info

Publication number: US1909756A
Application number: US503506A
Authority: US
Inventors: Wallace L Claypool
Original assignee: WESTCO CHIPPEWA PUMP Co
Current assignee: WESTCO CHIPPEWA PUMP Co; WESTCO-CHIPPEWA PUMP Co
Priority date: 1930-12-19
Filing date: 1930-12-19
Publication date: 1933-05-16
Anticipated expiration: 1950-05-16

Description

May 16, 1933. w CLAYPQQL 15909,?56

ROTARY PUMP Filed Dec. l 9, 1930 3 Sheets-Sheet 1 15 INVENTOR F .2; Zmwmvma ATTORNEYS) 7 May 16, 1933. w. 1.. cLAYPoOL 1,909,756

I 1 ROTARY PUMP v Fil9d Dec. 19, 1930 s Sheets-Sheet 2 [ff Wil INVENTOR BY w? ATTORNEYS Patented May 16, 1933 UNITED STATES PATENT OFFICE WALLACE L. CLAYPOOL, OF DAVENPOR'1,- IOWA, ASSIGNOR TO WESTGO-CHIPPEWA. PUMP COMPANY, OF DAVENPORT, IOWA, A CORPORATION OF DELAWARE ROTARY PUMP Application filed December 19, 1930. Serial No. 503,506.

This invention relates to rotary pumps, and more particularly to an improved casing for rotary pumps having an annular pressure-..

means for relieving the pressure at the stufl"-.

ing boxes which are disposed directly against the pressure in the inner chamber that lies inwardly of the pressure-developing chan- 15 nel.

Another object is to provide a casing for a pump of the character described which relieves the pressure against the stufling boxes, so that the stufling box packing need not be held so ti htly around the pump shaft that scoring 0 the shaft may result.

Another object is to provide a casing for a pump of the character described with a by-- pass between the inner chamber and the suction side of the pressure-developing channel in order to reduce the pressure in the inner chamber to substantially suction pressure, thereby eliminating the necessity of packing the rotor shaft against the discharge pressure.

With the above and other objects in view which will be readily apparent from the following detailed description, the present in vention consists in certain features of construction and combination ofv parts which will be readily understood by those skilled in the art to which the invention appertains.

In a pump of the character described having a circumferential pressure-developing channel that is defined by the cooperative relation of the sides of the pump casing and web of the pump rotor, there is a considerable difference in pressure between the pressuredeveloping channel and the inner chamber surrounding the rotor shaft that lies inwardlyof the pressure developing channel. Any leakage from the pressure-developing channel. into the inner channel surrounding the pump shaft has a tendency to force its way into the suction side of the pressure-developmg channel, due to the difl'erences in pressures.

Because of the close clearance between the opposed flanges of the casing and the rotor, there is a pressure built up in the inner chamber which communicates directly with the stufiing boxes. In this type of pump it has been necessary to exert a relatively hi h pack ng pressure on the stuffing box pacilng in order to prevent leakage of liquid through the stufiing boxes, and the consequent injury to the stuffing boxes. This is quite objectionable because of the tendenc of the tight packing to score the rotor sha and because of the production of excess friction, which reduces the efliciency of operation of the pump. Leakage is wasteful and presents a fire hazard when the pump is handlin inflammable liquids such as gasoline, petro products, etc.

The present invention contemplates, in order to overcome these disadvantages, the use of a by-pass from the inner chamber to the suction side of the pressure-developing channel to relieve the pressure in the inner chamber and so that suction pressure only will prevail in the inner chamber, therefore making it necessary to pack against suction pres sure only and not against the discharge pressure.

Referring to the accompanying drawings, in which like numerals refer to like parts throughout the several views,

Figure 1 is an end elevation of one type of pump embodying the presentinvention, 85 a portion of the pump casing being broken away to show the pump passageways and the stuffing box in section;

Fig. 2 is a view of the pump with the re-v movable casing portion removed to show the rotor and the pump passageways, a portion of the rotor being broken away to show the entrance of the by-pass into the inner cham- I ber surrounding the pump shaft;

Fig. 3 is a section of the pump taken substantially on the line 3-3 of Fig. 1, showing the by-pass leading to the suction side of the Pump; Fig.4 1s a view similar to Fignfl, showing the use of a modified form of by-pass between the pressure-developing channel and the inshown in Fig. 6.

The embodiment of the invention that I have chosen to illustrate in the drawings comprises a pump casing formed of mated casthe pressure.

ing portions

1 and 2 that are connected by means of outwardly extending flanges 3 and 4 that are held together by suitable screws 5. Each of the

casing portions

1 and 2 has an outwardly extending tubular boss 6 and has a suitable adjustable packing land 7 mounted therein to retain the pac ing 7a about the rotor shaft 8 to prevent leakage between the respective casing portions. It is to be noted that the packing gland 7 is threaded into the opening of the boss 6 surrounding the shaft 7 so that the packing 7a can be compressed about the rotor shaft 8.

The rotor 9 is secured to the shaft 8 by a suitable key 10, and the shaft is supported in suitable'out-board bearings 11 and is provided with an extension to provide a suitable driving means. The out-board bearings 11 are sup orted by u per and

lower arms

11a and 11 respective y, which are formed integral with the

casing portions

1 and 2. A deformable packing ring 13 is mounted in registered annular grooves 14 in the casing portions to prevent leakage between the easing portions.

he pump assembly is supported on pedestals 15 that are formed on the portions 1 of the casing.

Projecting inwardly from each of the

casing ortions

1 and 2 are opposedannular ribs or anges' 16 which, in cooperation with the web 17 of the rotor 9, define the pressure developing passageway 18 of the pump.

Radially extending portions 20 of the flanges 16 of the

casing portions

1 and 2 extend across the passageway 18 as far as the outer edge of the rotor buckets to form a deflecting ahutment and restriction'in the pressure-developing passageway of the ump. This abutment directs the flow of liqui from passageway 18 through an outlet port 21.

The space betwen the flanges 16 of the mated casing portions is only suflicient to permit unrestricted operation of the motor web 17 therebetween, thus preventing any substantial radial flow of liquid from the pressure-developing passa e of the pump inwardly along the web of t e rotor. The cooperating extended portions 20 restrict the resa.

sure of the passageway at the outlet end t ereof to substantially the cross-sectional dimension of the pump rotor, only suflicient clear- "rotor and carried completely aroun ance being provided to permit the unrestricted operation of the rotor buckets between them. Direct flow of the liquid from the outlet to the inlet passage is thus prerespectively, are-formed in oppositely extending horizontal portions of the fixed casing portionl, as shown in Figs. 1 and 2, the removable casing portion 2 being so designed as to unite with the fixed casing portion 1 and cause the proper direct communication of the inlet and

outlet passageways

26 and 27 with the pressure-developing channel. The main portion 1 of the Pump casing has the cylindrical sleeve 28 ormed therein, and the inlet passage 26 opens into the cylindrical side wall of the sleeve 28 in registered relation with a continuation of the passage that is formed in the main casing 1.

The removable casing part 2 has a cylindrical face 29 that fits snugly within the sleeve 28 of the main casing. 'The continuation of the inlet passage 26 is formed by the spirally arranged passage that opens into the face 29 of the casing part 2 and also opens laterally into the casing face 30 that constitutes the defining wall of the pressure-developing channel. The sleeve 28 of the main casing overlies aportion of the curved passage to thereby form the remaining wall of the pressuredeveloping passage or channel; The inlet port opens. laterally into the pressure-developing channel immediately adjacent the extension 20 of the annular flange 16 that defines the inner wall of the pressure-developing channel. I

From the above description of the elements of the pump, it will be seen that liquid flows into the pump through the inlet 26 to inlet 'ports'located on opposite sides of the rotor.

After entering the pressure-developing channel 18 of the pump, the liquid is engaged by the liquid-engaging pockets of the pump the pressure-developing channel to the point where it is deflected tangentially from the pressure-developing channel'of the pump by the abutments 20 that closely fit the bucket portion of the rotor and merge into one wall of the outlet passage 27. The outlet port 21 is formed in the outer peripheral wall of the pressure-developing channelv 18 and serves to convey the liquid through the outlet in substantially a tangential direction relative to,

the directionof flow through the pressuredeveloping channel of the pump. Unnecess Slry deflection of the liquid in its passage from the pressure side of the pump to the distributing system is thereby avoided.

Referring to Figs. 1, 2 and 3, it will be noted that the chamber 40 surrounding the 5 hub 22 of the rotor 9 and rotor shaft 8 and lying inwardly of the circumferential flanges 16 formed on-the

pump casings

1 and 2, is placed in direct communication by means of a suitable conduit 41 with the suction side its opposite ends into the wall of the casing portion 1 defining the inner chamber 40 and into the wall of that portion of the casing 1 which defines the inlet passage 26. As pre; viously mentioned, any leakage from the pressure-developing channel into the inner chamber 40 has a tendency to force its way into the suction side of the pressure-developing channel, due to the differences in pressure, and, because of the close clearance between the casing portions and the rotor, there is a pressure built up in the area comprising the inner chamber 40 which communicates directly with the stuffing box packing 7a. This discharge pressure within the inner chamber 40 is relieved by the by-pass formed by the conduit 41 so that only a suction pressure prevails within the chamber 40, therefore making it necessary to pack against the suc- It has been necessary,

tion pressure only. heretofore, as previously explained, to pack the pump against the discharge "pressure and it is obvious that very material advantages can be obtained by employing the by-pass '41 from the inner chamber to the suction side of the pump. It is therefore unnecessar to exert a great deal of pressure on the stu g box, with the result that the pump shaft will rotate with much greater ease and thereby will be increased the efliciency of the pump since the friction is reduced to a minimum.

Another advantage is that, by the use of the by-pass from the inner chamber to the suction side of the pump, the pump shaft will not be scored by the use of relatively large pressures being exerted on the packing glands.

Further advantages are that the waste of valuable liquids such as calcium chloride brine, refinery products, etc., is prevented, and furthermore, that fire hazards are eliminated when inflammable liquids are being.

pumped.

Referring to Fig. 4, it will be noted that a modification of the pump structureshown in Figs. 1 and 2 is shown. In this construction a passageway 44 is formed in the rib 16 of the fixed casing portion 1, which causes a direct communication from the inner cham-.

her to the pressure-developing channel substantially at the entrance of the inlet passage 26 into the pressure-develo ing channel. The function of this construction is identically the same as that in the pump construction in Figs. 1 and A corresponding by,

of the pump. The conduit 41 is threaded at pump 50 and the second stage by the pump 51. In this construction the discharge of the I pump 50 is connected by means of the conduit 52 to the inlet side 53 of the pump 51. The inner chamber of the pump 50 is placed in communication by conduits 54 with the .suction side 54a of the pumpin the same manner as described in connection with Figs.

1 and 2. The inner chamber of the pump 51 is also provided with by-pass conduits 55 which join into a conduit 56 leading directly to the suction side 54a of the pump 50 as shown in Fig. 6. As previously described, the pressures within the inner chamber surrounding the rotors of the

pumps

50 and 51 are reduced to substantially suction pressure, since these chambers are placed in direct communication with the suction side of the primaryor first-stage pump 50.

It will be noted, however, that in all of the constructions only a suction pressure will prevail within the inner chamber because of the by-pass to the suction side of the pump, and that in these cases it is not necessary to pack against the discharge pressure of the pump, since only the suction vails in the innerchamber.

Aside from the specific embodiments of the invention herein shown and described, it will be understood that numerous details of the construction may be altered or omitted without departing from the spirit or scope of this invention, and I do not desire to limit the invention to the exact construction herein set forth as I desire to claim the same broadly as well as specifically, as indicated in the appended claims.

What I claim is:

1. A rotary pump comprising a casing having a circumferential pressure-developing channel and inlet and outlet passages comioo municating with said channel, a rotary shaft extending through said casing, a rotor '11,;

mounted on said shaft, buckets formed on the periphery of said rotor and lying within said channel. annular ribs on said casing en-- .by the pressure of liquid discharged from said channel, said by-pass comprising a recess in one of said ribs openin at one end into said chamber and at the ot er end into said channel substantially at the suction side thereof. a

'2. A rotary pump comprising a casing having a circumferential pressure-developingchannel and inlet and outlet passages communicating with said channel, a rotary shaft extending through said casing, a rotor mounted on said shaft, buckets formed on the periphery of said rotor and lying within said channel, annular ribs on said casing engaging the sides of said rotor with a running fit for closing in said channel and providing a chamber around said shaft, packing glands carried by said casing and surrounding said shaft, and a by-pass in one of said annular ribs extending from said chamber and open-- ing into said channel substantially at the suction side thereof for maintaining a low pressure in said chamber.

3. A rotary pump comprising. a casing having a circumferential pressure-developing channel and peripheral inlet and outlet passages communicating with said channel, a rotary shaft extending through said casing coaxial with said channel, a rotor fixed to said shaft and having peripheral buckets lying within said channel, annular ribs on said casing engaging the sides of said rotor with a running fit for closing in said channel and providing a chamber around said shaft, packing glands carried by said casing and surrounding said shaft, and a recess in one of said ribs placing said chamber in communication with said channel substantially at the opening of said inlet passage into said changel to maintain a low pressure in said cham- 4. A rotary pump comprising a rotor having a web portion and a peripheral bucket portion, a casing enclosing said rotor, means in said casing defining a peripheral pressuredeveloping channel wherein fluid is engaged by said bucket portion, said means being in runnin engagement with said web portion, a cham r in said casing radially inwardly of said channel, a rotary shaft extending through said chamber for supporting and rotating said rotor, peripheral suction and discharge passages in said casing opening directly into said channel, stop portions in said channel for diverting fluid in said channel into said discharge passage, and a passageway inv said means opening into said channel substantially adjacent said suction passage and opening into said chamber whereby to maintain the pressure in said chamber substantially at suction pressure.

In testimony whereof I aflix my signature.

WALLACE L. CLAYPOOL.