US1326064A - Packing-ring. - Google Patents

Description

H. KELLER.

PACKING RING.

TION man JULY .APPLICA 9,19l8- 1,326,064. Patented Dec. 23,1919.

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HULDREICH KELLER, OE ZURICH, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSGHAFT DER MASCHINENFABRIKEN ESGHER WYSS 8600., OF ZURICH, SWITZERLAND.

PACKING-RING.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Application filed July 9, 1918. Serial N 0. 244,101.

Z '0 all whom it may concern:

Be it known that I, I-IULDREIOH KELLER, a citizen of the Republic of'Switzerland, residing at Zurich, 'Hardturmstrasse 19, Switzerland, have-invented certainnew and useful Improvements in Packing-Rings;

and I do hereby declare the following to be .a clear, full, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention. has reference to improvements in packing rings for horizontal shafts and relates more particularly to improved means for balancing or equalizing the gravity of such rings. The invention specifically consists in theprovisionof at least one recess in the inner circumferential surface of the ring, the recess being open toward the high pressure side and closed toward the low pressure side if the recess is above the shaft and closed toward the high pressure side and open toward the low pressure side if the recess is below the shaft. 7

The counterbalancing arrangement can be so made, that the cylindrical internal surface of the ring is provided with a recess at its top side and a recess at its bottom side, the former being open toward the high pressure side and closed toward the low and the latter being open toward the low pres sure side and closed toward the high pressure side.

. Packing rings for horizontal shafts, such as are found in steam turbines and the like, are required to readily adapt themselves to the position of the shaft, so that they are freely supported thereon or float, as; the saying is. But such rings, owing'to the gravity action, have the tendency to cling to the shaft, remaining thereby in continuous operative contact with it, and in consequence unduly wearing out. The result is a steadily increasing leakage with all its troubles.

As a remedy it has been proposed to support the packing ring by suitably arranged steel springs; but such springs, when subjected for any length of time to the high temperatures found for instance in the high pressure chamber of a steam turbine, soon lose their initial elasticity and become useless for their purposes; besides which, they quickly rust and break.

The balanced packing ring according to the present invention, effectively obviates all these drawbacks and will keep in full operative function for an indefinite period.

An embodiment of the invention will now be described in detail in connection with the accompanying drawing in which:

Figure 1 represents a vertical section through a constructional example of the improvement, as intended for use in a steam turbine;

Fig. 2 shows a fragmental vertical crosssection thereof, and Fig. 3 represents a diagrammatic plan.

In Fig. 1 of the drawing the numeral 1 denotes a fragment of the partition wall dividing a high pressure stage having a pressure p, from the succeeding stage having a lower pressure 79 of a steam turbine. The carbon packing ring 2 is divided along the horizontal plane and the two halves are operatively held together by the circumferential spiral spring 3. The ring, under the steam pressure acting on it from the left to the right (p -p is pressed against the inner surface of the partition wall 1, so as to form a steam tight joint.

In order to counterbalance the gravity of the packing ring 2 with its spring 3, two tongue-shaped recesses are provided within the inner circun'iference of the carbon ring symmetrically to the vertical middle plan :000 (Fig. 2). The upper recess 4 opens toward the left, that is to say toward the high pressure chamber and is closed toward the low pressure chamber by the wall-thickness A--B. The lower recess 5 is. open toward the right, that is to say tothe lower pressure side, and is closed toward the high pressure side by the wall-thickness CD. In the upper recess consequently approximately the full high pressure p, will obtain, and in the lower recess approximately the full lower pressure 39 As shown diagrammatically in Fig. 3, the upper recess has the dotted-line shape EAF, and the lower recess the outline G-H-D, and the two recesses partly overlap to the extent of the cross-shaded portions AK-DJA, with the result that the carbon ring will be acted on by a force which is substantially equal to the product of the area AK-DJA, measured in square centimeters, and the diflerence of the specific steam pressures p and p measured in kilograms/square centimeters, thus we have:

ring half, which open section is under full high pressure, and since an open sectlon (recess 5) of the lower ring half is diametrically opposite to the closed section AV B of the upper ring half, which recess 5 is under full low pressure, it is obvious that the non-overlapping surfaces EJ DKFE and G-JA-KH-G exert persurface unit only about one half of the balancing effort exerted by the overlap surface AJDK-A.

By properly dimensioning the recesses, the forces acting on the carbon ring halves from within will equalize the gravity and thus counterbalance the ring.

In case theweight of the ring is light and the difference between the specific steam pressures p, and p, is considerable, then it suffices to provide only one such recess. But in this instance a recess in the upper ring half must face the high pressure chamber andmust be closed toward the low pressure chamber, while a recess provided in the lower ring half must face the low pressure chamber and must be closed against the high pressure.

If, however, the weight of the parts to be counterbalanced is considerable, then it will be necessary to provide two oppositely disposed recesses for correspondingly large dimensions, as shown by way of example in the drawing.

The recesses may be also subdivided latorally, that is to say in circumferential direction, in suitable manner, for instanceby ribs or webs.

What I claim is:

1. In packing rings for horizontal shafts, the arrangement for counterbalancing the gravity of the ring comprising at least one recess in the inner circumferential surface of the ring, the recess being open toward the high pressure side and closed toward the low pressureside if the recess is above the shaft and closed toward the high pressure side and open toward the low pressure'side, if the recess is below the shaft, substantially as set forth.

2. In packing rings for horizontal shafts, the arrangement for counterbalancing the gravity of the ring, comprising a recess at the top side and a recess at the bottom side of the cylindrical internal surface of the ring, the former recess being open toward the high pressure side and closed toward the low pressure side andthelatter recess being open toward the low pressure side and closed toward the high pressure side, substantially as set forth.

3. In packing rings for horizontal shafts,

the arrangement for counterbalaneing the gravity of the ring, comprising a subdivided ring, spring means for holding-the ring together, the ring having at least one pressure recess in its cylindrical internal surface to one side of its horizontal axial plane, this recess being open toward the high pressure side and closed towardjthe low pressure side if it is above the shaft, and closed toward the high pressureside and open toward the low pressure side if it is below the shaft, substantially as set forth.

4. In packing rings for horizontal shafts, the arrangement for counterbalancing the gravity of the ring comprising a'subdivided ring, spring means for holding'thering together, a recess at the top side and a re cess at the bottom side of the cylindrical internal surface of the ring, the-former recess being open toward the high pressure side and closed toward the low pressure side and the latter recess being opentoward the low pressure side and closed toward the high pressure side, substantially as set forth.

5. In packing rings for horizontal shafts, the arrangement for counterbalaneing the gravity of the ring, comprising one or more recesses situated to one side of the horizontal middle plane of the ring, said recesses being in the inner circumferential-surface of the ring and open at one of the pressure sides of the ring and closed to the other pressure side, said recesses when positioned above the shaft being closed to the low pressure, and when below the shaft being closed to the high pressure side.

In testimony that I claim the foregoing as my invention I have signed my name.

HULDREICH KELLER.

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