US2037293A - Pump packing - Google Patents

Description

in the associated pump housing; in the provision of a, packing of; the threadedv type which will retain yits compression irrespective of the direction o-f rotation ofthe pump shaft; and in the provision of a packing particularly suitable for the Patented Apr. 14, 1936 UNITED STATES PATENT OFFICE PUMP PACKING William N. Weinman, Columbus, Ohio ApplcationMarch 1, 1935, seriaivN. 8,922

, 4 Claims.

This invention relates `to improvements in pump packings and has for its! object theprovision of. an improved packing bywhich theescape of liquid from the associated pump housing :through the joints surroundingthe operating shaft of the pump .is effectuallyv precluded.

)Other objects of. the inventionv are: the provision of-a packingfor surrounding a rotatable shaft wherein the rings of compressible material, formed in connection with the packing, .are placed under compression by a follower mounted to move longitudinally of the associatedshaft to compress the pac-king byv a straight longitudinal movement -to prevent binding strains or stresses frocrnbeing fl'5` vsiredl rotary motion; the provision of apacking l wherein the followeradvances into engagement imparted to the shaft and interferingvwith its dewith the packing by the actionof an internally threaded nut-which is disposed concentrically with respect to the longitudinal axis of the associated shaft; a packing provided with means. for

maintainingv a liquid seal therein to preventthe passage of atmospheric air through` thel packing land-into thev housing ofthe pump; in the-'provision of a packing which may loe-easily andi readily adjusted to maintain the 'compressible packing-materials under desired` compression; Y in the vprovision of -meansfforpreventing the escapeof liquid through then-packing when the shaft is stationary and high back pressures exist on the fluid protection of ane-electric motor when the'latter is employed to drive directly thev shaft of the pump-and-is disposed in relatively close proximity to the pump housing.

f motor driven centrifugal pump, the packing comprising the invention being disclosed in elevation; -Fig:3 is a vertical 'longitudinal sectional view v*taken through the packing;

"FgA is a transverse-verticalsectional View of the packing on the plane indicated bythe line IV-IV of Fig. 3;

Fig. 5 is an enlarged detail longitudinal sectional view taken through the packing.

Referring more particularly to the drawing, the

, numeral I designates the: casing of a pump, the

latter being shown in this instance as of the centrifugal type and is formed internally with an impel1er 2formed 'with an axial liquid inlet 3 Awhichcommunicates with a plurality rof outwardlyl and radially disposed nozzles 4, the inlet .3 being arranged in registration with the open end of a liquid supply pipe: 5 threaded in the hub extension 6 of thecasing I, there being a wear-receiving ring. l disposed between the impeller and the hub 6. The kimpeller is further formed with a hub 8 whichreceives the vreduced outer end 9 of the armature shaft I Ilgof an electric motor I I, which may be of the reversible type. The casing I isalso provided with a tangentially disposed liquidl outlet I2, shown as provided with a discharge pipe I3. Thegeld frame I4 of the motor' II is provided with a tubular extension I5 which is disposed Jbetween the motor I I .and the pumpcasing I bywwhich the pump casing may be secured rigidlybut separately with the motor frame.

In a pump, arrangement of this character, considerable difficulty has been encountered in maintainingfthe packing which surrounds the'motor shaft suiiciently tight to overcome leakage through the packing and its'` injurious` contacting with theV operating parts of the motor Il. Usually; these motors operate at high speeds and -if,.there is but small leakage through or past the packing, the same is apt to be disseminated ini the form of a spray over the motor. The: usual packing vcomprises a follower fo-r placing the compressilole material of the packing under compression. .It has been customary to providethe 0pposite and outer sides of this follower .with openingsfor the reception yof spaced stud bolts: projecting rigidly from the pump casing and equipped with. nuts or other threaded devices which lare separately actuated to draw the follower into desired clamping engagement with the compressible .packing rings. As a matter of practice, it is difficult to tighten the securing members for the follower on both sides thereof to an equal degree, but unless this is done, the follower doesY not move inwardlyin -a` straight longitudinal line in true concentric relationship with the pump shaft, the

result being that laterally directed pressures and undue friction is applied to the motor'l shaft causing excessive wear thereof and a packing` which 'does not .confine liquid to the pump casing,

In order to improve this customary packing construction and to overcome the objections which I nd inherent in them, the inner vertical wall I5 of the casing I is formed around the shaft I9 with a box extension I'I, which is disposed concentrically with respect to the shaft I0 and is suitably spaced therefrom to produce an annular packing-receiving socket I8. Rotatable with the shaft I9 is a pressed-on sleeve I9 which at its forward end engages with the impeller hub 8 of the pump, the sleeve I9 rotating Vin unison with the impeller and its operating shaft. Surrounding the outer portion of the sleeve I9 and disposed within the socket I3 are packing rings 2U of suitable compressible materials, the said rings being also received within a cage 2| positioned in the socket I8 around the sleeve I9. The inner end of said cage is provided with a flange 22 which engages with the sleeve I9, an annular recess being formed thereby between the sleeve I9 and the cage 2| for the reception of the packing rings 29, the inner of said packing rings engaging with the flange 22, as disclosed in Fig. 3.

The forward end of the cage 2| is provided with an outturned annular flange 23, the outer face of which is formed to engage with a key ring 24. The peripheral portion of the ring 24 is provided with radially projecting lugs 25, which are received within recesses 26 provided in connection with the outer portion of the flange 23, as shown in Fig. 4. Likewise, the ring 24 is provided with an inwardly projecting key lug 2'I which is disposed to be received within a longitudinally extending slot 28 provided in connection with a threaded follower 29. This follower comprises a tubular metallic member which is externally threaded as at 30 and has its inner tubular end disposed to enter the annular recess formed between the sleeve I9 and the cage 2|, whereby to press directly upon the packing rings 29. The outer end of the follower terminates in an annular enlargement 3|, in which is formed an annular recess 32, surrounding the shaft I0. The enlargement 3| of the follower includes a socket for the reception of a fibrous ring washer 33, which is removably held within the recess 32 by a threaded ring 34 carried by said follower.

Mounted upon the threaded end 39 of the follower is an adjusting collar 35, which is internally threaded as at 36 for the reception of an externally threaded ring 3l, the latter being disposed for engagement with the rear surface of the flange 23 of the cage 2|, thereby preventing longitudinal travel of the collar 35 when the latter is rotated with respect to the follower, since the cage 2| has a press iit in the socket I8 formed in the extension I'I. It will be seen, however, that by rotating the collar 35, longitudinal movement will be imparted to the follower 29 since the latter has threaded connection as at 39 with the collar 35, and in view of the fact that the follower 29 can not rotate due to the interposition of the keyring 24. Thus the rotation of the collar 35 merely causes the follower 29 to move longitudinally of the shaft I0 and in true coaxial relationship therewith, thereby compressing or releasing pressure upon the packing rings 29. In effect, therefore, the collar 35has a swiveled connection with the outer end of the pump box I'I.

If desired, the cage 2| may be provided intermediate of its length and on its outer surface with a shallow annular groove 38, which registers with a plurality of longitudinally aligned ports 39 arranged in registration with a ported metallic lantern ring 4U, which is disposed between the packports of the ring 4B into contact with the sleeve I9. This serves to produce a liquid seal in the packing which prevents air drawn from the atmosphere from passing into the interior of the pump when the latter is operating under conditions causing the formation of a high vacuum. The ring washer 33 in the outer end of the follower is also of material value in protecting the motor II when the pump is not operating. Frequently, there exists on a pump of this kind a high hydrostatic back pressure which tends to cause the discharge of liquid through the packing toward the motor. Any back pressure liquid which finds its way through the packing and into the groove formed internally of the annular enlargement 3| of the follower is obstructed by the ring washer and prevented from escaping from the packing.

It will be observed that in the operation of the packing, in order totighten or compress the rings 20, it is necessary merely to rotate the collar 35, which being swiveled on the outer end of the cage 2|, a stationary member, causes the longitudinal movement of the follower 29 in a true axial and longitudinal direction with respect to the shaft I0, thus relieving the shaft of undue binds, friction or pressure by reason of the tightening of the packing. The shaft may rotate in -either direction without interfering with the utility of the packing even though an annular threaded member is employed for placing the packin rings under compression.

While I have described what I consider to be the preferred form of my invention, nevertheless it vwill be understood that the same is subject to conpacking members of a compressible material surrounding said shaft and disposed between the latter and said sleeve, an exteriorly threaded follower positioned upon said shaft and movable longitudinally with respect thereto to regulate the .compression of said packing members, a rotatable collar having a threaded axial opening for the reception of the threads of Said f o1lower,and a key ring having inwardly and outwardly projecting lugs, the outwardly projecting lug of the key ring being received within the recess of said vsleeve and the inwardly projecting lug of said ring being received within a longitudinally ex tending slot provided in said follower.

2. Apacking comprising a casing for the reception of 'a rotatable shaft, there being an annular open-ended socket provided between said casing and said shaft, a non-rotatable sleeve positioned in said socket, said sleeve terminating at one end in an outwardly directed flange having arecessprovided in `its outer face, a collar swiveled for rotation in connection with said zfiange, an iexteriorly threaded tubular follower movable longitudinally of said shaft, packing members of comp-ressible material disposed between said sleeve and said shaft and engaged by one end of said follower to regulate the compression of said members, said follower being threadedly received within an axial opening provided in said collar, and a ring having outwardly and inwardly projecting lugs, the outer of said lugs being received Within the recess provided in the outer flange of said sleeve, the inner of said lugs being received within a longitudinal slot .provided in said follower.

3. A stun-lng box comprising a sleeve member provided vwith an open ended, concentric socket, said sleeve having an external flange formed upon its socketed end, said flange havingI a recess formed therein, an internally threaded collar, means for swivelling said collar to the flanged end of said sleeve, an externally threaded follower carried by said collar and slidable in the socket in said sleeve, said follower being provided with a recess, and a washer member provided with internal and external projections positioned between the flange on said sleeve and said collar, said projections being positioned in the recesses in said flange and follower and serving to lock said follower in non-rotatable relationship with said sleeve.

4. A stuffing box comprising a sleeve member provided with an open ended socket, an external flange formed with the socketed end of said sleeve, said anged end of said sleeve being provided with a radially extending recess, an externally threaded follower slidably received within the socket in said sleeve, said follower having a longitudinally extending recess formed in its outer wall, key means positioned in the recesses in said flange and follower for connecting said follower and sleeve in non-rotating relationship, and an Y internally threaded collar swivelled to said flange and serving to move said follower into and out of the socket in said sleeve and to confine the sleeve and follower connecting means in the recess in said flange.

WILLIAM N. WEINMAN.

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