US1881723A - Pump - Google Patents

Description

Oct. 11, 1932. H. s. LEE 1,881,723

PUMP

Filed July 15. 1929 2 sheets-sheet 2 IN VEN TOR.

/arfy Lee MMM A TTORNE Y.

Patented Oct. l1, 1932 .UNITED/f STATES PATENT OFFICE .r HARRY S. LEE. OF DETROIT, MICHIGAN PUMP applicati@ mea my 15, 192s. serial No. 378,287.

handlinga liquid containing an abrasive subp stance, such as sand, cement or the like.

Pumps of this nature are used in cement manufacturing plants for pumping the slurry, which is a wet mixture containing cement. The cement, of course, is extremely abrasive, and it has been found that the packing box, or stuffing box of the pump very rapidly becomes useless or worn out once the cement attains access thereto, inasmuch as the cement Wears away the packing material. It follows that the pump can only be used for a relatively short While, until it has to be torn down and a new stuffing box placed therein. It has been proposed to provide these slurry umps with a water seal instead of a dry stu ng box, but this is objectionable because it adds a material amount of water to the mixture, thus requiring more energy and the use of more coal or other fuel to dry the mixture.

One of the reasons why the stuffing box of a slurry pump is so short lived is that the impeller shaft vibrates in its operation, and as a result, there is a wearing away of the packing material, or in any event, the packing material is somewhat loosened on the shaft, thus allowing the abrasive mixture to enter, and once the abrasive mixture attains access to the packing material, it is a matter of a very short time until the stuiing box is completely destroyed as such.

This invention contemplates an arrangement of a stuffing box and other associated parts of the pump, wherein the abrasive mixture will be prevented from having access to the packing material for a relatively long period of time, and with this in view, an arrangement is provided wherein the stuiing box is so mounted with relation to the shaft that the shaft vibrations will not cause a wearing away or mis-shaping of the packing material. More speciically, the invention contemplates the provision of a floating, dry,

' stuffing box so mounted as to move with a vibrating shaft somewhat in a oating manner as regards the pump housing. Furthermore, the invention contemplates the employment of an additional rotary pum -like member which is arranged so as to e ect a pumping action, which tends to draw the slurry away from the packing box.

In the accompanying drawings:

Fig. l is a sectional view taken through a pump constructed in accordance with the invention, showing the mounting of the stuifing box and various details of the structure.

Fig. 2 is a composite section and side elevational view of the pump ,empellel Fig. 3 is a yview of one of the head plates i of the pump.

Fig. 4 is an enlarged section taken on line 4-4 of Fig. 3.

Fig. 5 is a side view of one of the spring retaining devices employed in conjunctionA with a spring for effecting pressure on the packing material.

Fig. 6 is a view of a clamping ring member employed in the mounting of the floating stuffing box.

Fig. 7 is a view illustrating a sealing collar used in the construction for effecting a flow tendency which keeps the. slurry away from the stuffing box.

In the drawings there is shown a shaft 1, journaled in bearing 2 in casing or housing 3, and this shaft is driven as by means of a suitable motor (not shown). The shaft may be connected to the shaft of an electric motor, or it may be driven by employing a belt and pulley wheel, or the like. On the end of this shaft there is mounted the impeller 5 of a pump, so that the shaft in its rotation, rotates the impeller. The impeller shown is one of the type having impeller blades, or vanes 6, confined between spaced radial walls 7 and 8. Outside of the walls are vanes 9 and 10 which may be described as being continuations of the impeller blades 6. These function in a manner as will be later set forth.

The pump housing, or casing, comprises an annular member 15, having secured thereto, head or closure members 16 and 17. The invlet for the material to be pumped is shown. at

' ing assembly and disassembly of the parts,

is at 19. The impeller works between liner discs 20 and 21 which are replaceable, :and which are preferabl ,provided with a plurality of lugs 22. ese lugsl 22 may of soft metal cast directly onto the hard hner plate and machined to fit the member 15 as shown in Fig. 1. This arrangement ma es it unnecessary to machine the liner plates as a whole. The head member 16 and liner plate 21 have a central aperture which provides. for thevinlet, while the liner plate 20 relatively closely hugs the hub portion of the impeller, and the closure plate 17 is shaped in such -manner that the packing box can be disposed to seal the point where the shaft passes through the closure member 17.

The stuiiing box comprises .packing 25, which i-s disposed over the shaft and which is confined within a sleeve 26. This sleeve has a iange 27 which frictionally engages a sealing collar 28, the sealing collar being mounted on the shaft to rotate therewith, and the frictional engagement takingv place at the point 29. This sealing collar is provided with vanes30 so that in its rotation, it efects a umping action away from this point of frictional contact. The sleeve 26 may also be recessed for the reception of a packing ring 31, which frictionally enga-ges the sealing collar and aids in the seal at this point. p

The packing 25 is confined at one end by an internal shoulder 32 on the sleeve 26, `and at the other end by a collar member 33. This collar is slidable longitudinally of the shaft, and is backed up by `a coil spri 34. The coil spring 34 may be in turn bac ed up by any suitable stationary part, as for example, the supporting member 35 which connects the pump housing with the shaft housing. However, there is preferably provided, packing 36 for retaining lubricant for the bearing 2, and the spring 34 may advantageously be placed between collar 33 and a similar collar 37, which backs up against the packing; 36. These two collars 33 and 37 may be provided with apertured ears 38, through which screwthreaded bolts 39 extend. By employing screw-threaded nuts on these bolts, spring 34 may be held in a compressed manner durand these bolts or studs may be screwed into the base portion 35 during operation to insure that these collars do not rotate.

The stuffing box, which includes the packing substance 25, is floated upon the shaft,

tures in the member 17, therubber rings, and the metallic rings 41. These bolts are tightened down so as to make a sealed connection at this point.

These rubber rings are likewise sealed to the sleeve 26, and accordingly, the rubber rin are bent so as to take substantially an L s ape in cross section. Clamps 45 having ears 46 are placed over the rubber rings where they lie drawn tig tly into position b the means of suitable bolts or screws 47. T e rubber rings upon the packing material in the stuiing box is ruined in a very short time. Moreover, when'the pump is stopped, the material in the conduits disposed at an elevation higher than the pump, flows by action of gravity into the pump and completely lills the same against the sleeve 26, and then are ofthe shaft. Some so that the abrasive material 1s in close prox-A imity to the stuing box; this makes it very essential that the stuffing box be perfect in order to allow no abrasive material to enter the same.

It will be noted that in accordance with this invention, the packing material 25 is floating; that is to say, it is not bound tightly to any, part of the pump housing or other stationary part, but mounted so as to be freely movable with the shaft. In other words, the pacln'ng 25 is free to vibrate bodily with the shaft, at whichtime the rubber rings 40 flex', thus permitting this action. Accordingly, the vibrations in the shaft do not pound against the `packing in such manner as to cause imperfections in it, as the packing rides with the shaft so to speak.

In the operation of the pump, the vanes 9 and 10 act to set up aV pumping action, thus preventing an accumulation of the material handled outside of the impeller. Also, the vanes 30 on the sealing collar l28 effect a pumping. action in the nature of a suction away from the contact point 29 and the packing so as to tend to keep the material handled away from these parts. It will be noted that should the pump be stopped that the material handled, having a sulicient head outside the pump, will flow in between the impeller and the liner plate 20, then through space 50, where it is stopped from further flowing by the stuilng box. When the pump is started, the blades 9 draw this material out away from the stulling box, while the blades 30 tend to keep the same away from the stuing box. If, however, there should be a defect in the packing material, as may be caused by shaft vibrations as heretofore, the abrasive substance creeps into the same, and then, when the pump is started, this abrasive substance rapidly destroys the sealing action of the stuilng'box. v

The contact 29 may be lubricated by means of an oil cup, or other similar .lubricating device 51, communicating through pi 52 and channel 53 in the sleeve 26 to this ring. It is advantageous to refer to a ump constructed in accordance with this mvention, as a slurrypump for use in cement handling, but of course, the invention is a plica-4 vble to pumps for all kinds of uses, as or example, the pumping of water carrying sand or the like, orA for pumps used any place where there is one or more elements in the water or other Huid handled, which is liable to attack the packing material.

I claim:

1. In a pump, a housin an impeller, a shaft upon which. the impe ler is mounted, a stuffing box comprisin a collar, packing material confined within t e collar and engaging the shaft, flexible means connecting the collar and housing, and a sealing disc mounted to rotate with the shaft and having frictional engagement with the collar inside the pump housing. v

2. In a pump, a housin an impeller, a shaft upon which the impe er is mounted, a stuing box comprisingla collar, packing material confined wlthin t e collar and engaging the shaft, flexible means connecting the collar and housing, and a sealing disc mounted to rotate with the shaft and having frictional engagement with the collar inside the pump housmg, and vanes. on the'sealing disc arranged to effect a pumping action away from the point of frict1ona1 contact during pump operation. l

In testimony whereof I aix my si ature.

HARRY S. E.

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