US2777395A - Pump and packing thereof - Google Patents

Description

Jan. 15, 1957 Filed March 12, 1952 n. R. DlsBRow 2,777,395

PUMP AND PACKING THEREOF v 2 Sheets-Sheet lv TTORA/EX .Jan. 15, 1957 D. R. DlsBRow 2,777,395

PUMP AND PACKING THEREOF Filed March l2, 1952 2 Sheets-Sheet 2 IN V EN TOR.

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United States Patent PUMP AND PACKING THEREOF Donald R. Distri-ow, Battle Creek, Mich., assiguor to Union Steam Pump Company, Battle Creek, Mich.

Application March 12, 1952, Serial No. 276,110

11 Claims. (Cl. 10S-111) This invention relates to improvements in pump and packing thereof.

My present invention is in general an adaptation of an improvement upon the invention of my application for patent filed April 6. 1951, Serial No. 219,573, now Patent No. 2,741,991.

The principal objects of this invention are:

First, to provide a centrifugal pump in which a portion of the fluid being pumped is circulated across or upon certain sealing elements of the packing to prevent excessive heating thereof and the formation of gas pockets around the seal.

Second, to provide a high pressure centrifugal pump in which the shaft packing is highly eflicient and durable and is arranged so that it cannot be tampered with or rendered ineffective by the operator or other workmen.

Third, to provide a packing for the shaft of a high pressure centrifugal pump which permits substantial reduction in the overhang length of the shaft, thereby minimizing the springing of the shaft and permitting closer tolerances between the shaft and its packing.

Fourth, to provide a packing assembly for the shaft of a high pressure centrifugal pump in which the pressure within the pump acts to retain the packing gland in position.

Fifth, to provide a pump and shaft packing therefore which because of the resistance of the packing to leakage or blowouts or other failures is well adapted for handling of high pressure and high temperature volatile or dangerous fluids. t

Sixth, to provide an effective means for cooling the packing and associated parts.

Objects relating to details :and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which:

Fig. i is a fragmentary view, mainly in longitudinal section, of a pump embodying the features of my invention which certain parts being shown infull lines for convenience in illustration.

Fig. 2 is an enlarged fragmentary view of portions shown in Fig. l and correspondingly sectioned. v

Fig. 3 is an enlarged fragmentary view in section on a line corresponding to line 3-3 of Fig. 2.

ln the embodiment of my invention illustrated in the accompanying drawing 1 represents the body of the pump and 2 the head thereof which is detachably secured to the body of the pump by cap screws 3. The body portion of the pump is provided with a base and supporting pedestal 4. i

The body 1 is provided with an impeller chamber 5 for the impeller 6 which has radial blades 7 with passages 8 therein. The intake 9 of the impeller opens axially tothe intake passage 1l). The impeller chamber has an annular discharge 11 surrounding the impeller and opening to a discharge conduit not illustrated.

2,777,395 Patented Jan. 15, 1957 The body member 1 and the head member 2 are provided with bearings 12 and '13 respectively for the journal members 14 and 1S of the impeller. The impeller shaft 16 is supported in bearings designated generally by the numerals 17 and 1% which are spaced longitudinally of the shaft and carried by the bearing member 19 secured to supports 2li on the head member by means of cap screws 21. The bearing member might be mounted directly upon the pedestal or other support but it is desirable to mount it as illustrated as this facilitates alignment.

The pump head member 2 is provided with a gland box 22 through which the shaft 16 extends. The gland boX has an inwardly facing shoulder 23 at its outer end. The body member 2 has an annular recess 24 providing an inwardly facing shoulder 25 for the flange 26 of the packing gland 27 which is secured upon the shoulder by the cap screws 2S. The gland has an inwardly projecting annular flange 29 at its outer end forming a thrust seat for the non-rotatable packing seal member 3G fitting within the gland and having a close but preferably nonfrictional fit around the shaft. The coacting rotatable seal member 31 is connected to 'the shaft to rotate therewith through the combined coupling and thrust collar 32 which is arranged on the reduced portion 33 of the shaft 16. This reduced portion of the shaft is provided with a keyway 34 which receives the key 35 engaging groove 3a in the collar 32 and it also receives the key 37 for drivingly connecting the impeller to the shaft. The impeller is secured upon the shaft by means of the nut 3S on the threaded end 39 of the shaft.

The seal member 31 is drivingly connected to the collar 2 by means of a plurality of angularly spaced pins 40 only one of which is illustrated in Fig. 2. A plurality of springs 41 are disposed in supported `thrust engagement with the collar 32 to yieldingly urge `the seal member 31 against the coacting seal member Sil which is commonly designated as a seal bearing member. A gasket 42 is provided between the inner end of `the collar 32 and the shoulder 43 on the hub of the impeller. A resilient packing 44 is arranged in a groove 4S to coact with the driven sealing member 31.

In assembling these parts, assuming that the packing gland has been positioned in the head member with the seal member 30 therein, the key 3S is inserted in the keyway and the assembled parts 31, 32 with the thrust springs 41 and the `driving pins 42 are positioned with the key 35 engaging coacting groove 36 in the collar 32. The ring S4 is then inserted to retain these parts in their assembled relation and to retain them while assembling the impeller.

The head member 2 denes a circulating chamber 46 in which these seal members are positioned. This chamber is continuously supplied with fluid being pumped. A conduit 47 is connected to the discharge chamber of the pump and `directed to discharge upon the seal members 30 and 31 as is illustrated in the drawing. The impeller is provided with circulating passages 48 to insure circulation in the chamber 46 and prevent the forming of gas pockets therein surrounding the packing.

In the commercal structure some circulation may occur through the impeller and this is desirable to prevent overheating of the bearings. The head member 2, as stated, is provided with an inwardly facing shoulder 23 which provides a thrustsupport for the outer gland member 49 in which annular packing members 5t), 51 and thrust member 52 are disposed. These packings are desirably of non-rectangular section as illustrated so that the thrust thereon tends to expand them into sealing engagement with the shaft.

A coil spring S3 is supported by the inner end of the gland member 27. The tension of this spring being such as to maintain a constant thrust upon the packing memavv'aaee bers 50, 51 and thrust member 52 to maintain their sealing relation to the shaft and thus provide a durable seal or packing with all the packing internally arranged so that such pressure thrust as it may be subjected to in the operation of the pump tends to urge the packing elements to sealing position. Further, the thrust upon the packing gland 27 does not impose any load upon its fastenings and the packing elements are all internally positioned so that they are not accessible for manipulation by workers or operators which frequently results in destroying the efficiency of the packing or seal if not in destroying some part thereof, or causing damage to such an extent that replacement is required, thus necessitating shutting down the pump for a substantial period with serious interruption of the use of associated apparatus.

The packing box of the head member is chambered t receive the the packing gland and to provide a cooling and circulating chamber 54- which is connected to the reservoir 55 by the feed or supply conduit do and the return conduit 57. in this embodiment illustrated, the circulation is gravity circulation, the parts being associated so as to produce a very substantial thermo-Siphon action caused by the fluid being heated in the chamber S4 and circulated through heat exchange mediums. 'l' he cooling liuid indicated at 58 is desir-ably a lubricant.

The inner gland member 27 is provided with radial openings 59 opening to the internal annular groove 159 which surrounds the seal member 30, this prevents the seal member 3i) from becoming overheated. Further, in the event that the pump runs dry through failure of the source of supply of the fluid pumped the lubricant or iiuid in the chamber 54 passes between the shaft and seal member 30 to the coacting sealing surfaces or faces of seal members 30 and 31 keeping them lubricated so that they do not burn out so that they are not seriously injured even though the pump shall run dry or cease to pump for a very considerable period of time.

In the embodiment illustrated the bearing member t9 for the shaft bearings 17 and 1S is cored or otherwise provided with chambers 60 surrounding the bearings 17 and 18. These chambers are connected by the conduit 61 to the reservoir 62 which is connected to a suitable supply of cooling fiuid through the conduit 63. A section of the conduit 56 passes through this chamber 62 to cool the liquid 5S circulating through the conduits 56 and 57 and the reservoir 55.

ln the embodiment illustrated the reservoir 55 is partially supported by the support 163 carried by the bearing member 19. The support 163 constitutes an outlet connection for the bearing cooling system. The lubricant for the bear-ings 17 and l?, may be supplied to the charnber 64 through oil cup 65 indicated by dottedlines in Fig. l. Packings 66 and 67 are provided for the bearings 17 and 1S.

By positioning the packing glands within the head member instead of externally thereof the overhang of the shaft is greatly reduced. This reduction ranging in some commercial designs from 4 to 16 inches. in the embodiment illustrated the shaft is well supported by two bearings but the overhang, that is, the distance from the bearings to the impeller has been greatly reduced as a result of the arrangement of the packing gland on the inner side of the head member. Further, the packings cannot be blown out by high pressure within the pump and they are protected from manipulation by the operator, which might cause damage thereto. The packing elements are loaded to predetermined spring pressure.

The reservoir 55 is provided with a gas vent 70 having a restricted orifice 7l preferably formed in a disc '72 seated within the coupling 73. The pipe 74 is provided with a filler plug 75 and With a testing valve not shown. The pressure operated signal 76 is connected to the reservoir 5S by the pipe 77. The pressure operated signal designated by the numeral 76 may be of any desired type.

A balie 7S is disposed above the normal liquid level in the reservoir and below the openings of the venting connection 70 and the signal connection 77 to the top of the reservoir.

The embodiment of my invention illustrated is highly desirable for use in the pumping of volatile iluids at high pressures and high temperatures such, for example, are frequently met in distillation systems the manufacture of synthetic rubber and various other materials. Although the seal is highly eiicient minute quantities of fluids being pumped may escape through the seal into the circulating oil and if in liquid form will ash into vapor and bubble up through the circulating oil tending to build up a vapor pressure in the oil reservoir. During normal operation the vapor will escape through the small orifice of the relief vent but if the sealing assembly should become inelhcient due to wear or other reasons and the volume of escaping material increases to above a predetermined degree the alarm will be operated. The baliie 73 serves to separate the oil and vapor, that is, prevents or minimizes the carrying of oil through the vent.

l have not attempted to illustrate and describe other embodiments or adaptations which I contemplate, as it is believed that this disclosure will enable those skilled in the art to adapt my invention as may be desired.

Having thus described my invention what l claim as new and desire to secure by Letters Patent is:

l. In a centrifugal pump, the combination of, a casing comprising a body member, a chambered head member detachably mounted on the body member and having a gland box provided with an inwardly facing annular shoulder at its outer end and with an inwardly facing recess surrounding said gland box, an impeller, said body and said head members being provided with bearings for said impeller, an impeller shaft disposed through said gland box, a first gland member disposed in said gland box and having a flange at its inner end seated in said recess in said head member, said gland member having an inwardly extending annular ange at its outer end, a non-rotatable sealing member disposed in said gland member in thrust supported relation to said flange thereof, a spring biased sealing member connected to said shaft to rotate therewith and in axial thrust engagement with said non-rotatable sealing member, a conduit opening t0 the discharge of the pump and discharging upon said sealing members in the chamber of said head member in the'plane of contact between the sealing members, said impeller having a circulation opening therein connecting said head member chamber with the intake of the pump, a second gland member disposed within said gland box and seating against the said shoulder thereof, a packing disposed within said second gland member to coact with said shaft and including a thrust element, a coil thrust spring for said packing disposed between its said thrust element thereof and said first gland member, a cooling liquid supply having a circulating connection with said gland box, said first gland member having an internal groove surrounding said non-rotatable sealing member and in communication with said gland box.

2. In a centrifugal pump, the combination of, a casing comprising a body member having the pump intake formed therein, a chambered head member detachably mounted on the body member and having a gland box provided with an inwardly facing recess surrounding said gland box, an impeller, said body and said head members being provided with bearings for said impeller, an impeller shaft disposed through said gland box, a gland member disposed in said gland box and having a tiange at its inner end seated in said recess in said head member, said gland member having an inwardly extending annular flange at its outer end, a non-rotatable sealing member disposed in said gland member in thrust supported relation to said flange thereof, a spring biased sealing member connected to said shaft to rotate there-` with and in axial thrust engagement with said non-rotats, able sealing member, a conduit opening to the discharge of the pump and discharging upon said sealing members in the chamber of said head member adjacent a point of engagement between said sealing members, said impeller having a circulation opening therein connecting s aid head member chamber with the intake of the pump, and', a.

cooling liquid supply havingV a circulating connection with said gland box, said gland member having an internal groove surrounding said non-rotatable sealing member and in communication with said gland box.

3, In a centrifugal pump, the combination of, a casing comprising a body member, al chambered head member detachably mounted on the body member and having a gland box provided with an inwardly facing recessV surrounding said gland box, an impeller, said body and said head members being provided with bearings for said impeller, an impeller shaft disposed through said gland box, a gland member disposed in said gland box and having a flange at its inner end seated in said recess in said head member, said gland member having an inwardly extending annular ange at its outer end, a nonrotatable sealing member disposed in said gland member in thrust supported relation to said flange thereof, a coacting spring biased sealing member connected to said shaft to rotate therewith within the chamber of said head member, a conduit opening to the discharge of the pump and discharging upon said sealing members in the chamber of said head member adjacent a point of engagement between said sealing members, said impeller having a circulation opening therein connecting said head member chamber with the intake of the pump, and a cooling liquid supply having a circulating connection with said gland box, said gland member having an internal groove surrounding said non-rotatable sealing member and in communication with said gland box, and a bearing member detachably mounted on said head member and provided with a bearing for said shaft disposed closely adjacent to the outer side of said head member, said bearing member having a cooling fluid chamber formed therein in heat transfer relation to said bearing, and iiuid connections for supplying cooling liquid to said bearing member associated in heat exchange relation to the liquid supply for said gland box.

4. A seal between a rotating shaft and a casing into which the shaft extends and subject to internal pressure comprising, a head member having a gland box provided with an inwardly facing annular shoulder at its outer end, a shaft disposed through said gland box, a first gland member disposed in said gland box and having a flange at its inner end seated on the inner side of said head member, said gland member having an inwardly extending annular flange at its outer end, a sealing member disposed in said gland member in thrust supported relation to said flange thereof, a coacting spring biased sealing member connected to said shaft to rotate therewith, a second gland member disposed within said gland box and seating against the said shoulder thereof, a packing disposed within said second gland member in outwardly seating relation to coact with said shaft, a thrust spring for said packing disposed between it and said first gland member, and a cooling liquid supply having a circulating connection with said gland box, said rst gland member having an internal cooling passage formed therein opening to the exterior of said first sealing member and circulating passages opening between said cooling passage at opposite sides thereof and said gland box.

5. .ln a centrifugal pump, the combination of, a casing comprising a body member, a chambered head member detachably mounted on the body member and having a gland box provided with an inwardly facing shoulder at its outer end, an impeller, said body and said head members being provided with bearings for said impeller, an impeller shaft disposed through said gland box, a first gland member disposed in said gland box from the inner side of the head member and in outward thrust sustaining engagement therewith, said gland member having 'an inwardly facing shoulder at its outer end, Iavsealing member disposed in said gland member in Ithrust supported relation to said shoulder thereof, a coacting sealing member connected to said shaft to rotate therewith, a conduit opening to the discharge of the pump and discharging upon said sealing members, said impeller having a circulation opening therein connecting said head member chamber with the intake of the pump, a second gland member disposed within said gland box and seating against the said shoulder thereof, a packing disposed within said second gland member to coact with said shaft and to close the louter end of the gland box, 'a thrust spring for 'said packing disposed between it and said first gland member, and a cooling liquid supply connected to circulate through said gland box.

6. In a centrifugal pump, the combination of, a casing comprising a body member, a chambered head member detachably mounted on the body member land having a gland box provided with an inwardly facing shoulder at its outer end, an impeller, said body and said head members being provided with bearings for said impeller, lan impeller shaft disposed through said gland box, a gland member disposed in said gland box from the inner side of t-he head member and in outward thrust sustaining engagement therewith, a sealing member disposed in said gland member, a coacting sealing member connected to said shaft 'to rotate therewith, a conduit opening to the discharge of the pump and discharging upon said sealing members in the chamber of said head member adjacent a point of engagement between said sealing members, said impeller having `a circulation opening therein connecting said head member `chamber with the intake of the pump,

` a cooling liquid supply having a circulating connection with said gland box, a bearing support member `abu-tting the outer side of said head member, and a bearing for said shaft supported in said bearing support member and disposed closely adjacent to the outer side of said head member.

7. A seal between a rotating shaft and a casing into which the shaft extends and subject to interna-l pressure comprising a head member having a gland box provided with an inwardly facing shoulder at its outer end, 'a shaft disposed through said gland box, a first gland member disposed in said gland box from the inner side of vsaid head member and having outward axial thrust sustaining engagement therewith, said gland member being of a diameter exceeding the diameter of the opening at the outer end of said gland box, a sealing member disposed in said gland member in supporting engagement therewith `and receiving said shaft, a coacting sealing member carried by the `shaft and disposed on 'the inner side of the head member, a second 4gland member disposed within said gland box and having outward thrust `supporting engagement with said shoulder thereof, said second gland member being of a diameter exceeding that of the opening at the outer end of said gland box so that it can be inserted and removed only from the inner side of the head member, a packing disposed within said second gland member -to coact with lthe second gland member to close the -outer end of the gland box, a thrust spring for said packing disposed between it and said first gland member, and a cooling liquid supply connected to circulate through said gland box.

8. A sea-l between a rotating shaf-t and a casing into which the shaft extends and subject to internal pressure comprising 'a head member having a gland box, a shaft disposed through said gland box, a first gland member inserted in said gland box from the inner side of said head Imember and having outward axial thrust sustaining engagement therewith, a sealing member disposed in said gland member in supporting engagement therewith and receiving said shaft, a coacting sealing member disposed on said shaft at the inner side of the head member, a second gland member disposed within said gland box and having outward thrust supported engagement therewith, said second gland member being introduced into said gland box from the inner side of said head member and being in outward axial thrust supported engagement therewith, a packing disposed within said second gland member and coacting therewith to close the outer end of the gland box, and a liquid supply connection for said gland box.

9. In a centrifugal pump, the combination of, a casing comprising a head member having a gland box, a gland member inserted in said gland box and seated on the inner side of said head member to resist outward thrust thereon, an impeller shaft disposed through said gland member and having a reduced portion on which an impeller is mounted and provided with a longitudinal extending keyway, a first sealing member disposed in said gland member in outward axial thrust sustaining engagement therewith, a coacting second sealing member, a coupling collar sleeved upon the reduced portion of said shaft and keyed thereto by a key disposed in said keyway, a ring for retaining said collar to the assembly of the impeller on the shaft disposed on said shaft, said impeller being sleeved upon and drivingly connected to said shaft by a key disposed in said keyway at the inner side of said ring, driving pins connecting said collar to said second sealing member, and springs disposed between said collar and said second sealing member to yieldingly urge the same against said rst sealing member.

l0. In a centrifugal pump, the combination of, a casing comprising a body member, and a head member detachably mounted thereon and having a gland box, a' gland member inserted in said gland box and seated on the inner side of said head member to resist outward thrust thereon, an impeller shaft disposed through said gland member and having an impeller on its inner end, a first sealing member disposed in said gland member in outward axial thrust sustaining engagement therewith, a coacting second sealing member, a coupling collar sleeved upon said shaft and keyed thereto, said impeller being sleeved upon and drivingly connected `to said shaft at the inner side of said col-lar and in annular thrust and sealing engagement therewith, driving pins connecting said collar -to said second scaling member, and springs disposed between said collar and said second sealing member to yieldingly urge the same against said tirst sealing member, said second sealing member and said coupling member having telescopically interfitting portions with a packing ring sealingly engaged therebetween.

ll. ln a centrifugal pump, the combination of, a casing comprising a body member, and a head member detachably mounted thereon and having n gland box, a gland member inserted in said gland box and seated on the inner side of said head member to resist outward thrust thereon, an impeller shaft disposed through said gland member and having an impeller on its inner end, a iirst sealing member disposed in said gland member in outward axial thrust sustaining engagement therewith, a coacting second sealing member, a coupling collar sleeved upon said shaft and keyed thereto, said impeller being sleeved upon and drivingly connected to said shaft at the inner side of said collar, driving connections for said collar to said second Sealing member, and a thrust spring for said second sealing member supported by said collar.

References Cited in the tile of this patent UNITED STATES PATENTS u we..

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