US811833A - Packing for elastic-fluid turbines. - Google Patents

Description

No n,ass. PATBNTED FEB. s, 1906.

W. L. R. BMMET.

PACKING 5'03. ELASTIC FLUID TURBINES.

' APPLRH'IIGX nun JULY 19, mm.

2 BHEETB-SHBET 1.

Witnesses: V inventor William 125111111611 3 QM; many.

' of narrow radial grooves 13 running in UNITED STATES PATENT OFFICE.

WILLIAM L. R. EMMET, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

PACKING FOR ELASTlC-FLUID TUHBINES- Specification of Letters I'atent.

Patented Feb. 6, 1906.

Application filed July 19, 1904. Serial hi0. 217,211-

a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Packin s for Elastic-Fluid Turbines, of which the fol owing is a specification.

This invention relates to means for making a fluid-tight joint at the point where a rotating shaft passes out of a stationary casing containing elastic fluid under pressure.

The invention is especially useful in packing the shaft of a steam-turbine, where the peripheral speed of the shaft is high and the steam-pressure is relatively heavy.

It is found that packing-rings of carbon,

usually containing a certain amount of graphite to act as a lubricant, are durable and efficient if the pressure between the surfaces is not too great; and the present invention consists of means for adjusting and maintaining the proper pressure in a packing of this kind.

For convenience the invention will be illustrated and described in connection with a steam-turbine of the Curtis (vertical) type; but it will be evident that it is not necessarily confined to that kind of a machine.

In the accompanying drawings, Figure 1 is a vertical section 0 a portion of a steam-turbine embodying my invention. the invention applied to a two-eta e turbine. Fig. 3 is a horizontal section, and l 'ig. i is a vertical section of a modification.

The shaft 1 is shown as carrying two bucket-wheels 2 3, each operat' in its own steam-chamber 4 5, the upper wlieel receiving :live steam from the chest 6 and the lower wheel using the exhaust steam from the upper wheel through the nozzle 7. The shaft passes up throu h a central opening in the dome or top 8 o the casing, and it is at this point that the packin is used which forms the subject-matter of t '5 application.

Secured to the shaft and rotating therewith is a collar or shoulder 9 of suitable construe tion, on whose upper edgr; rests the carbon packing-ring 10, w ich is mly held in an anmllar holder 1 1, having an inwardly-pro'cctingflange 12, hearing on top of the car on. The upper edge of the collar 9 has a plurality from its outer edge to a small groove concentric with the shaft, and the 'fiange 12 has a simi- Fig. 2 shows lar set of narrow radial grooves-14, running from its inner ed e to a small groove concentric with the sha t, the two small grooves lying substantially at the middle of the carbon. The holder 11 fits in a gland 15, which is screwed into the opening in the dome 8. A key or s line 16 in a vert cal ke way compels the hcl er 11 to rotate with tile gland, hut permits the holder to slide vertically therein.

The gland has an inwardl -prcject1ng flange and the inner edges 0 the flanges 12' 1.5

. are connected by a steam-tight movable '}'cint,such as an accordion-spring 17, of sheet metal,brazed to said flanges. Instead of this constructionxl 'me use the modification shown in Fig.\4, W ere the flane l2.is extended u past the flange 15 an the joint is made tig t by a stuffing-box 18. V

in order to exert a positive mechanical pressure on the packing-ring, I prefer to arrange a set of springs 19 between the flanges 12 and 15. Their tension is supplemented by steam-pressure admitted from the cham; her 4 through ports 20 into the space above the holder 11. The orts are preferably made in the holder, as s own.

To revent leakage steam from escaping into t e engine-room, the gland may be inclosed by a cover 21, provided with an escapepipe 22 to carry off any steam that may leak .past the packing ring. The joint between the cover and the shaft is packed by means of an ordinary stuffing-box having soft packing 23 and a screw-gland 24. Since the gland 15 is inclosed, some means must be provided for adjusting it from the outside. A sirn le mode of accomplishing this is shown. he edge of the gland is formed with gear-teeth meshing with a pinion 25 on a short shaft 26, extending through the cover 21 and carrying ahevei-gear 27, which meshes with a bevelplmon 28 on an o crating-shaft 29, provided with a hand-whee 30.

The operation of the device is as follows: Since the steam has free access to the space above the holder, it will exert a downward pressure on thepaokin ring, which is partly or nearly balanced b 1 t e steam enterin the radial grooves 13 in t e collar. The mechanical pressure exerted by the springs 19 can be closely adusted by screwing the gland 15 in or out. This ad 'ustaoility also provides for taking up wear. he grooves 14 in the flange 12 permits a free escape of any steam that may leak between the acking-ring 10 and the holder 11,wliich mig it otherwise destroy the predetermined ratio of balancing ressures on the opposite sides of the pac ingring. Should the ring wear unevenly, the 1ncreased leakage of steam from the grooves 13 in the collar would cause a greater drop in pressure through said grooves, and thus to a certain extent reduce the upward lift on the ring, thereby causing greater resultant downward pressure thereon and tending to counteract and correct the uneven wear.

I have shown the packing located on the high-pressure end of a turbine; but it can be used on the low-pressure end as well. Where a step-bearing is rovided and supported at a point within the ase containing an exhaustchamber, the packing can be located on top of the bearing-casing or at any convenient point. Where such a construction is employed, the shaft 29 should extend through the wall of the casing and the hand-wheel 30 be located outside. In using my improved construction as a vacuumpacking I may make some slight changes to suit the new condition, but the essential features will remain as before.

In accordance with the provisions of the Patent Statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the inventioncan be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

l. The combination with a shaft having a collar, of a packin -rin resting on said collar, an annular hoflder or said ring, a gland surrounding said holder, and springs between said gland and holder.

2. The combination with a shaft having a collar, of a acking-ring resting on said col lar, an annu lar holder for said ring having a flange bearing thereon, a gland surrounding said holder and having a flange, a steamtight connection between said flanges, and orts leading into the space between said anges.

3. The combination with a shaft having a collar provided with radial grooves, of a carbon acking-ring resting on said collar, an annular holder for said ring having a flange bearin thereon and ports passing t irough it, a gland splined on said holder and having a flange, and a steam-tight connection between said flanges.

4. The combination with a shaft having a collar provided with radial grooves, of a carbon packing-ring resting on said grooved collar, an annular holder for said ring provided with ports and having a flange bearing on said ring, a gland splined on said holder and having a flange, a steam-tight connection between said. flanges, and springs between said flanges.

5. The combination with a shaft having a collar provided with narrow radial grooves running from the outside partly across the same, of acarbon acking-ring resting both on the grooved an ungrooved surface of the collar, and means for exerting a pressure on said ring.

6. The combination with a shaft having a collar, of a carbon packin -ring resting thereon, and an annular hold er having a flange bearing on the ring and containing radial grooves runnin part way across the ring.

7. The comblnation with a shaft having a collar, of a packing for said shaft resting on said collar, a rotatable screw-threaded gland, springs between said gland and packing, a casin inclosing said parts, and means for rotatlng said gland from outside said casing.

In witness whereof I have hereunto set my hand this 18th day of July, 1904.

WILLIAM L. R. EMMET.

Witnesses:

EI NJAMIN B. HULL, HELE ORFORD.

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