US1308454A - Packing for turbine-shafts and the like. - Google Patents

Description

PACKING FOR TU IIIIIIIIIIIIIIIIIIIII E.

A P P L l C A T l 0 N F l L E D A U G 9 I 9 I 8.

Ffiowzea z m/w W. F. SOMES.

' PACKING FOR TURBINE SHAFTS AND THE LIKE.

APPLICATION FILED AUG-9. I918. 1,308,454, Patented July 1, 1919.

2 SHEETS-SHEET 2.

Z064 ZZ'e v ii 54:2 E76 6 a i j 'ITED STATES PATENT OFFICE.

WALTER F. SOMES, F BOSTON, MASSACHUSETTS.

PACKING FOR TURBINE-SHAFTS AND THE LIKE.-

isomer.

Tn packing turbine shafts it has been cus tomary to employ a plurality of rings made up of segments, the rings being disposed side by side within the wall of the turbine casing with their juxtaposed faces bearing tightly against each other so as to prevent steam from passing therebetween. These segmental rings are diflicult to manufacture and adjust, and what is more serious in turbine practice is thatthe high steam .pressure within the turbine forces these rings so tightly together that. the wear between the juxtaposed surfaces of the respective rings is excessive.

The principal object of the present invention is to provide a packing for steam turbine shafts and the like in which the bearingmembers are not forced together by the steam pressure so as to produce undue wear. This object is attained by arranging the packing members so that the members are subjected to no unbalanced steam longitudinally of the shaft Other objects of the invention will be apparent from the following description and accompanying drawings, in which,

Figure 1. is a longitudinal central section of one embodiment of my invention;

Fig. 2 is a transverse section on line 22 of Fig. 1;

Fig. 3 is a'central longitudinal section of another embodiment of the invention; and

Fig. 4 is a transverse section on the line 44 of Fig. 3.

In Figs. 1 and 2 T have illustrated my invention as being applied to a turbine, 1 representing a turbine casing, and 2 the turbine shaft. The packing is mounted in a cap 3, which is secured to the end of the easing 1 by means of stud bolts 4.

The embodiment of my invention illustrated in Fig. 1 comprises a sleeve 5 which is secured to the shaft 1 in any suitable Specification of Letters Patent.

pressure Patented July 1, 1919.

Application filed August 9, 1918. Serial No. 249,050.

manner as by a pressed fit, key connection, by belng formed integrally with the shaft, or by means of a set-screw such as illustrated at 6 in Fig. 1. The sleeve 5 extends beyond the end of the cap 3 and at its outer end is provided a packing of any suitable type, as for example the ordinary packing illustrated in Fig. 1 which comprises packing material 7 confined in an annular recess between the end of the sleeve 5 and the cap 8. v

, The main packing joint is between the rings 9 and 10, which are preferably formed ofbabbitt and cast iron respectively. These rings are continuous and their contacting surfaces are preferably curved from inside to outside, as shown in Fig. 1. The ring 10 is prevented from rotating by means of pin 11 or in any other suitable manner. The sleeve 5 is providedwith a flange 12 near its inner end and the ring 9 is provided with a flange 13 ,which extends over the flange 12. A packing 14 of any suitable type is preferably provided between the flanges 12 and 13, as illustrated for example in Fig. 1.

The ring 9 is arranged to rotate with the sleeve5 and this may be effected in any suitable manner, as for example by means of pins 15 projecting from the flange 12 into the sockets 16 in the ring 9. Springs 17 are provided in sockets in the ring 9 to engage the. flange 12 and yieldingly urge the ring- 9 against the ring 10. Any suitable number of pins 15 and springs 17 may be employed, the pins and springs being suitably spaced about the shaft, and if desired the pins and springs may be disposed in the same sockets with the pins extending along 'the axes of the springs. In order to lubricate the contacting surfaces between the rings 9 and'lO a lubricant cup 18 is arranged to communicate with the space between the rings \9 and 10 through pipe 19 and a duct 20 extending lengthwise through the ring 10. The ring 10 and flange 12 have the same external diameter so that the steam pressure existing in the space 21' exerts equal and opposite forces on the opposite ends of ring 9 inasmuch as theefi'ectlve end areas 22 and 23 of the ring 9 which are exposed to the steam pressure are equal,

of steam through this space. Inasmuch as the ring 9 rotates with the sleeve 5 there is very little danger of steam escaping between the flanges 12 and 13, so that asmall packing of the ordinary type such as shown at 14 is adequate to prevent loss of steam through this space. Inasmuch as the ring 10 does not rotate relatively to the cap 3 it may be secured to the cap sufficiently tightly to prevent the escape of steam between these two parts. a

The main packing joint, therefore, is the "joint between rings 9 and 10. This joint is kept tightly closed by means of the springs 17. However, the pressure between the rings 9 and 10 is not rendered excessive by the steam pressure in the space 21 around the rings for the reason that the effective areas of the opposite ends of the ring 9 which are exposed to the steam pressure are equal. Oil or grease is supplied to the main contacting surfaces between rings 9 and 10 from cup 18 through pipe 19 and duct 20. By making the contacting surfaces of the rings 9 and 10 radially curved in the manner shown the parts will automatically adjust themselves more closely together than if they were tapered or made perpendicular to the axis ofthe shaft and the curvature also tends to prevent the oil or grease from. being; thrown outwardly from the space between the rings. It will be understood that-the end thrust on shaft 2, if any, will be taken up in the ordinary manner by thrust bearings not shown.

' The embodiment shown in Figs. 3 and 4 comprises a turbine'casing 31 and turbine shaft 32, a cap 33 secured to the end of the casing 13 by means of stud bolts 34, a col lar 35 fastened to the shaft 32 in any suitable manner, as by being formed integrally therewith as shown in Fig. 3, two main bearing rings '36 and 37 formed of. anysuita'ble' bearing materials, as for example cast iron and babbitt respectively, an auxiliary cap 38 secured-to the outer end of the main cap 33 by stud bolts 39, and a lubricant cup 40 communicatin fwithuthe space between rings36 and 37 through pipe 41 and duct 42. As shown in Fig. 4, the main cap 33 is approximately elliptical in cr0sssection,

' while the auxiliary cup 38'is circular. The

ring 36 is arranged to rotate with the shaft 32 and for this purpose I have shown a pin 43 extending from collar 35 into an openm in ring 36, although it will be understoo that the ring '36 maybe otherwise secured to collar 35, that may be urged against like comprising a packing ri the ring 37 by means of springs such as spring 17 in Fig. 1, and that it may, if desired, be provided with a flange such as flange 13 in Fig. 1 overhanging the collar 35. The ring 37 is prevented from rotating by means of the pin 44 and is urged against the ring 36 by means of springs 45. The pipe 46 is preferably arranged to slide in an opening through the auxiliary. cap 38 as the ring 37 moves axially with respect to the auxlliary cap .38. -A packing 46 of any suitable type is provided between the ring 37 and the surrounding casing. Clearance is-provided between rings 36 and 37 and shaft 32 to permit the rings to adjust themselvesito each other.

The operation of the embodiment shown in Figs. 3 and 4 is similar to that of Figs. 1 and 2. However, instead of yieldingly urging theinner ring against the outer ring as in Fig. 1 the outer ring 37 is urged against the inner ring 36 in Fig. 3. The end thrust on shaft 32, if any, is taken up by the ordinary thrust bearings not shown, and it will be observed that there is no unbalanced end thrust produced on the ring 36 by steam pressure, inasmuch as it is disposed between the collar 35 and the ring 37 which are of equal external diameter.

Considerable clearance is provided between pinsll, 15, 43 and 44 and their cooperating recesses to permit relative movement of the bearing rings for the purpose of automatically adjusting the curved bearing faces of the rings tightly together.

From the above it will be apparent that there is no unbalanced steam pressure acting longitudinally on the rotating packing ring. The steam pressure acting on the packing rings therefore does not add to the friction between the relatively moving parts of the packing. Moreover, the packing rings are continuous and not segmental.

In certain of the claims I haveused the term gas pressure generically to include both air pressure and steam pressure.

1. A packing for turbine shafts and the like comprising a packing ring rotatable with the shaft, and a non-rotatable packing ring fitting against the rotatable ring so as to prevent steam. from escaping therebetween, the rotatable ring being balanced longitudinally of the shaft with respect to steam pressure thereon.

2. A packing for turbine shafts and the rotatable with the shaft, and a non-rotata) 'le packing ring fitting againstthe rotatable ring so as to prevent steam from escaping therebetween, both of said rin being balanced longitudinally of the sha with respect'to gas pressure thereon. I

. 3. A packing for turbine shafts and the like comprising a packing ring rotatable with the shaft, anda non-rotatable ring having a side face fitting against a side face of the rotatable ring so as to prevent steam from escaping therebetween. the rotatable ring being arranged to be Subjected to no unbalanced steam pressure longitudinally of the shaft.

t. A packing for turbine shafts and the like comprising a packing ring rotatable with the shaft. and a non-rotatable packing ring fitting against the rotatable ring so as to prevent steam from escaping therebetween. the rotatable ring having equal and opposite end faces exposed to the steam pressure so that the steam pressure thereon is balanced longitudinally of the shaft.

2 A packing for turbine shafts and the like comprising a collar fast to the shaft, a non-rotatable packing ring, and a packing ring interposed between said collar and said non-rotatable ring with its end face fitting against the end face of said non-rotatable ring. said collar and non-rotatable ring having substantially the same external diameter and said rotatable ring-projecting beyond said diameter so as to be subjected to equal steam pressures on its opposite ends.

6. A packing for turbine shafts and the like according to preceding claim 3 further characterized by means for yieldingly urg ing the two rings together.

7. A packing for turbine shafts and the like comprising a collar fast to the shaft, :1 non-rotatable packing ring surrounding the shaft. a rotatable packing ring interposed between said collar and non-rotatable ring, and means interposed between said collar and rotatable ring for yieldingly urging the rotatable ring against the non -rotatable ring. the rotatable ring being balanced l0ngitudinally of the shaft with respect to steam pressure thereon.

S. A packing for turbine shafts and the like comprising a collar fast to the shaft, a non-rotatable packing ring surrounding the shaft, a rotatable packing ring interposed between said colla' and non-rotatable ring. said rotatable ring having a flange extending along the periphenv of said collar. and packing means betweensaid flange and said collar. the rotatable ring being arranged to be subjected to .-lll)Sftllltltlll V no unbalanced steam pressure longitudinally of the shaft.

9. A packing for turbine shafts and the like comprising a sleeve fast to the shaft. means at the outer end of said sleeve for packing the space between the sleeve and shaft. a non-rotatable packing ring surrounding said sleeve. a rotatable packing ring interposed between said collar and non-rotatable ring. and means interposed between said collar and rotatable ring yieldingly to urge the rotatable ring against the non-rotatable ring. the rotatable ring being balanced longitudinally of the shaft with respect to steam pressure thereon.

10. A packing for turbine shafts and the like according to preceding claim 3, further characterized by means for supplying lubricantto the mutually contacting surfaces of said rings.

11. A packing for turbine shafts and the like according to preceding claim 3. further cln'iracterized in that the contacting surfaces of said rings are radiall; curved.

12. A packing for turbine shafts like according to preceding claim 3, characterized in that the rings are ferentially continuous.

13. A packing for turbine shafts and the like comprising a packing member rotatable with the shaft, and a non-rotatable packing member fitting against the side of said r0 tatable member so as to prevent steam from escaping therebet ween. the rotatable member being arranged to be subjected to no unbalanced steam pressure longitudinally of the shaft.

Signed by me at Boston. Massachusetts, this 30th day of July, 1918.

\VALTER F. SOMES.

and the further c1rcum-

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