US954212A - Balancing means for turbines. - Google Patents

Description

C. ROTH. BALANGING MEANS PoR TURBINBS.

APPLICATION FILED SEPT. 29, 1908. I 954,212., v Patented Apr. 5, 1910.

Vshaft subjected to an end thrust.

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CARL ROTH, OF ZEHLENDORF, NEAR BERLIN, GERMANY.

BALANCING- MEANS FOR TURBINES.

Specification of Letters Patent.

l atented Apr. 5, 1914).

Application filed September 29, 1968. Serial No. 455,366.

.To all whom 'it may concer/a:

Be it known that I, CARL Ro'rn, a citizen of the Confederation of Switzerland, and resident of t) Annastrasse, Zehlendorf, near Berlin, German Empire, have .invented certain Anew and useful `Improvements in Balancing Means for Turbines, 0i which the following is a specification.

This invention relates to the balancing ol' turbines used for driving a propeller or like The invention is applicable either to turbines of the overpressure type such as the Parsons turbine, in which the steam expands and the pressure falls in the movingl blades, or to turbines of the pressure typc in which the steam is expanded in tixed blades and the moving blades utilize the velocity energy of the steam, or to the Vvelocitytype, where the steam is expanded in nozzles, and the velocity energy of the steam is extracted in one or several steps; when several speed-steps are employed, guideblades are placed between successive steps which merely serve the purpose ot' changing the direction ot' llow oit the steam.

The specific kind of simple or mixed turbine to which the present invention relates, is that Ain which a Single labyrinth packing is employed and is located at the high pressure end of the turbine and in which the packing is only subjected to a part ot' the total pressure fall of the steam in the turbine. According to the present invention no balancing surfaces are provided on the exterior of the turbine drum, but the interior of said drum is closed ott' by a disk subjected on one side to the pressure at an intermediate point in the expansion ot the steam situated later than the overload supply inlet, while the interior oit' the turbine drum on the other side ot said disk is subjected to a low pressure. The labyrinthpacking which is arranged on the opposite side of the steam inlet to the blading on the turbine drum and casing, only takes the pressure ditlerence between the pressure ot' the entrance steam or steam at'ter it has been expanded through .nozzles and the pressure of the intermediate point. The remaining pressure fall in the turbine is utilized to exert a pressure on the closed disk against the end pressure on the propeller shaft. By omitting allbalaneing surfaces on the exterior of the drum the balancing of the propeller thrust is considerably simplified. The end thrust on the propeller varies ol course with the load, as also does the pressure :tall used for end balancing, so that automatic control ot the end balancing is obtained. ln addition to the end pressure on the turbine blades the only two 'factors entering into the calculation tor the end balancing are the diameter ot the disk subjected to the pressure di'tlcrence, and the amount ot the pressure difference. Since the diameter otthe disk determined by the diameter otE the turbine drum there only remains the determination ot the intermediate point in the expansion olf the steam with which the` interior o't the turbine druln on the high pressure side o't the disk is to be conncctrul.

Referring now to the accompanying d ra wings, which diagralnmatically illustrate this invention, Figure l is a diagrammatic cross section ot the upper halt ot a turbine, aeeording to this invention, `Fig. 2 is a section through the high pressure end ot a turbine showing a slightly modilied torni, Fig. 3 is a section similar to Fig. l showing the invention applied to a turbine with a forward and reversing part arranged in the same easing.

According to the form shown in Fig. l the turbine or propeller shajtt a is supported in the casing at both ends and carries at the high pressure end an open disk or radiating arms c on which the drum I is supported. The drum Z is provided at the high pressure end with a labyrinth-packing c' and the low pressure end of the turbine drum is connected to the shal't by a closed disk f. The casing Z) is provided with an inlet g arranged in front ot the labyrinth packing c and blading it is arranged on the turbine drum and easing on the opposite side ot' said inlet to that at which the labyrinth packing' is a rranged. A further inlet m tor steam supply during` overloading is provided in the casing and beyond this inlet a connection is provided from the blading to the interior ot the drum. The connection 7' is there'tore arranged later in the expansion ol the steam than the inlet m. The blading it on the drum is continued to the exhaust L' and the right-hand-side ol-| the disk j is exposed to the pressure of the exhaust steam. It will be seen that with this arrz'rngement the drum is of constant diameter throughout its length and no end balancing faces are provided on the exterior of the drum. The shaft a is continued outside the casing and carries the propeller n. The direction of the thrust on the propeller is that shown by the arrow 11 in Fig. l while the direction of the pressure on the turbine blades and also on the closed disk m is that of the arrow 7" in Fig. 1. When the end pressure on thea propeller shaft varies, the load on the tur-.

bine also varies and in consequence the pressure of steam passing through the opening alters.

As shown in Fig. 2 the turbine may be arranged as a mixed turbine by arranging the high pressure part as a velocity type of turbine. The velocity steps o receive steam from suitable nozzles and this steam then passes through the blading it. The turbine drum is provided with an opening j.

In Fig. 3 the turbine casing C62 is arranged to surround not only the forward turbine drum d but also the astern turbine 7). Between the astern turbine and the forward turbine within the drum there is arranged a closing disk g. The forward turbine drum is provided with an opening y'Z and the astern turbine drum with an opening jg through which steam passes from an intermediate point in the expansion of the steam in the turbine. Vhen going ahead at lower speeds steam enters through the opening g2 and for higher speeds steam enters through the openings g2 and n2. `When going astern steam is supplied through the inlet s. Exhaust takes place in both cases through the opening 7c. It will be seen that when the forward or reversing turbine is working, the other turbine is running idle in the condenser vacuum.

I claim l. ln combination, a propeller shaft, a

turbine drum on said shaft, a casing around said drum, a steam inlet and an exhaust outlet on said casing, blading on said drum and casing on one side of said inlet, a labyrinth packing on said drum and casing on the other side of said inlet, a closed disk within said turbine drum, an overload inlet on said casing, a connection from an intermediate point later in the expansion of the steam than said overload inlet, and opening to the interior of the drum on one side of said closed disk and on the opposite side of the labyrinth packing to the steam inlet, said disk being on its other side subjected to the pressure of the exhaust.

2. ln combination, a propeller shaft, a forward and reversing turbine drum on said shaft, a casing around said forward and reversing drums, steam inlets to said forward and reversing turbines and a common outlet, blading on said drums and casing on one side of said inlets and extending toward the common exhaust, labyrinth packings on said drums on the other sides of said steam inlets, a closed disk between said drums and connections from intermediate points in the blading on said drums to the interiors of said drums, substantially as and for the purpose described.

In witness whereof l have hereunto set my hand in the presence of two witnesses.

CARL ROTH. lVitnesses ERNST SPRUMSKI, ELIsE FRIESE.

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