US1686218A - Turbine aggregate - Google Patents

Description

Oct.22, 1928. I 1,686,218

. F. LJUNGSTROM TURBINE AGGREGATE Filed Dec. 25, 1924 2 sheet -sheet- 1 F197 1 Bag 2 F14 uanjwz'i'om j I a 0 I Oct. 2,1928.

' 1,686,218 F. LJUNGSTROM V TURBINE AGGREGATE Filed Dec. 26, 1924 2 Sheets-Sheet Patented Oct. 2, 1928.

IREDRIK LJUNesTRoM, or LIDINGO-BREVIK, SWEDEN, ASSIGNOR To AKTIEBOLAGET IJUNGSTROMS ANGTURBIN, 0F LIDINGO-IBREVIK, SWEDEN, A CORPORATION.

TURBINE AGGREGATE.

Application filed December 26, 1924, Serial No. 758,284, and in Sweden' December 14, 1923.

It has been previously proposed, particularly in connection with steam turbine installations on shipboard, to use turbine aggregates having two or more turbines connected \in series, from which turbines the power is transmitted by means of toothed gearings onto a common driving shaft. It is also known to divide the turbine aggregate into two or more parts for different steam pressures, whereby highand low pressure systems, or a high pressure-, one or more intermediate pressureand a low pressure system have been attained. In known installations of this kind, the turbine aggregate generally has occupied very much space, besides which it has been heavy and, consequently, not adapted to answer the requirements made upon mechanical constructions, i. e. that they shall be simple, of small dimensions, and light in weight. At the present stage of the art of steam engineering, when turbines can be built for high pressures and high numbers of revolutions with a greatly increased efliciency, it has also been proposed to arrange the high pressure system within a casing or the like carried by the exhaust conduit of the high pressure system, said conduit being rigidly secured to the supply portion of the low pressure system, the high pressure system then provided in the common casing consisting of one or more turbines, the speeds of which would be reduced by means of toothed gearings to the speed possessed by the low pressure turbine. The gear shaft running at the lowest speed and provided within the high pressure system has been disposed in the extension of the low pressure turbine shaft, the same being coupled to the latter by means of diaphragm couplings. Thus it has been possible to use high steam pressures and high numbers of revolutions, and the turbine has attained a very high efficiency, it is true, but the construction has been rather complicated, necessitating the employment of diaphragm couplings and preventing building the aggregate in a more stable and less spacious manner, on account of the necessity of mounting the low pressure turbine shaft in a number of places, and particularly between the twoparts of the turbine.

The present invention relates to an arrangement in such turbine aggregates, whereby a more compact construction may be obtained, while diaphragms or other resilient or flexible couplings become superfluous. The invention consists in that the high pressure system is carriedby a casing hung onto the casing of the low pressure systern, laterally of the shaft of the latter system, the driven gear of the high pressure system being rigidly mounted on said shaft. In the accompanying drawings, Fi gs. 1, 2, 3, 4, 5 and 6 show diagrammatically the positions of the high and the low pressure systemsrelatively to the bearings of the turbine shaft. of an embodiment of-the invention.

I In Figs. 1-6, 1 and 2 designate the blade systems of the. high pressure and the low pressure systems respectively. From the blade system 1 of the high pressure system the power is transmitted through a toothed gearing 3, 4 to the shaft of the low pressure turbine. the piping 6 first passes through the blade system 1 of the high pressure system and then through the blade system 2 of the low pressure system, after which it is conducted, in the direction of the arrow 7, to the condenser supposed to be situated, in this case, underneath the aggregate, but which condenser is not shown in the drawing.

According to the invention, the high pressure system is carried by a casing 20 which is hung, for example by a connecting device 21, onto the casing 22 of the low ressure system, laterally of the shaft 5. he exhaust steam conduit of the high pressure system is movably connected with the supply portion of the low pressure system, as is diagrammatically shown in Figs. 1-6. The toothed wheel 4 is rigidly mounted on the turbine shaft 5. Diaphragm couplings thus become superfluous to facilitate movement between two separate shafts, contrary to what haspreviously been the case. The

absence of the said diaphragm couplings makes it possible to arrange the casings 20 and 22 nearer one another, which is particularly the case in embodiments according to Figs. 1, 2' and 3, where no bearing separates these casings.

In Fig. 1, the two systems are shown as situated between the bearings 8 and 9 of the turbine shaft 5, whereas in Fig. 2 the two systems are located on the same side of the bearings 10 and 11 of theshaft 5. In the latter case the two'systems are; so to say,

Fig. 7 is a more detailed 'view' The steam entering through 1 previous figures.

mounted in an overhung fashion on the shaft 5. In Fig. 3 a modification is shown of the aggregate disclosed in Fig. 1, the shaft 5 having here, in addition to the bearings 8 and 9, a third bearing 12. Fig. 4 illustrates how the toothed wheel 4 is located between two bearings 13 and 14 while the blade system 2 of the low pressure turbine is mounted in an overhung fashion on the turbine shaft 5. Fig. 5 shows how the turbine shaft 5 is journalled in two bearings 15 and 16 in such a manner that the gear wheel 4 will be mounted overhung on the shaft 5. This embodiment is particularly suitable when the power is'to be taken out on the right hand side of the aggregate in this figure. Fig. 6 shows how the shaft is journalled in three bearings 17, 18 and 19, of which one bearing 18 is located between the two systems.

Thus it will be seen from Figs. 1-6, which illustrate some of the conceivable dispositions of the bearings for the aggregate, that the shaft 5 of the low pressure turbine may be mounted in a number of different ways, depending in each case on the prevailing local conditions, the casing 20 surrounding the high pressure system in no case hampering the desirable mounting of the shaft.

Fig. 7 shows a detailed embodiment of the invention, particularly the arrangement of the two casings relatively each other.- In this figure, which only shows the upper half part of a turbine aggregate according to the invention, the reference numerals are the same for the parts to be found in the Thus 5 denotes the shaft of the low pressure turbine, which shaft has the blade system 2 of the low pressure system arranged thereon, whereas the blade system 1 of the high pressure system is mounted on a shaft 23 from which the power is trans- -mitted through the toothed wheels 3 and. 4:

to the turbine shaft 5. The blade system 2 of the low pressure system is mounted in an overhung fashion on the shaft 5' which is journalled in the bearings 13 and 14. This construction thus corresponds to the embodiment which is diagrammatically shown in Fig. .4. The steam enters through the inlet 6, through nozzles or other devices, and is brought to the blade system 1 of the high pressure system whence it passes through the blade system 2 of the low pressure system whereupon it escapes, in the manner hereinbefore described, to a condenser, not shown in the drawing. As distinguished from the construction shown in the previous figures, the low 'pressure system here consists of three blade rims with guide blade rims pertaining thereto, while the high pressure system, as before, comprises three blade rims.

The high pressure system 1 is carried by a casing 20 or by a casing 24 rigidly connected to the first casing 20. The casings 20 and 24 are rigidly connected with each other by means of devices as at 25, and the casing 2a is hung onto the casing 22 of the low pressure turbine, about the bearing 14, as at 26. On the other side of the shaft 5, these casings 20 and 22 are also rigidly connected with one another, by reason of which the casings will follow the movements of each other, particularly adjacent the shaft. However, variations in length and volume are apt to take place in the material, especially in the casing 24: surrounding the high pressure turbine 1. In order to eliminate the strains due to temperature involved thereby, the casing 2a is movably connectedwith the casing 22. This mobility consists either in that the casing 22 is itself formed into a ring, or in that the casing is rigidly connected to an annular part 27 embracing a cylindrical portion 28 of the casing 2 1, said portion being of smaller diameter than the ring 27. Arranged between these parts 27 and 28, which are fitted into each other with a relatively great clearance, are resilient rings 30 functioning in the same way as, for instance, the piston rings of an internal combustion motor. As .these rings are fitted into grooves turned into the cylindrical portion 28, and are adapted to bear against the ring 27 only by their own resiliency, mobility is rendered possible both in an axial and in a radial direction between the casings 2 1 and '22, while maintaining a good tightening effect against the leakage of steam. It is to be observed that these annular packings are not disposed between parts moving with respect to each other on account of the operation of the engine, as is the case, for example, in the piston of a cylinder in an' internal combustion motor, but the rings may be said to be arranged between two rigid parts, a certain amount of spherical movement being permitted, however, between such parts.

According to the invention it will thus be possible to provide the adaptability required on account of the expansions of the material, exactly in the parts showing the greatest variations in length and volume of the material, that is, in other words, exactly in those parts where strains of the material are apt to set in. It is to be observed that the difference in temperature between the steam entering at 6 and the steam in the supply portion of the low pressure system "may amount to several hundred degrees.

Diaphragms or other resilient parts thus become superfluous and, consequently, the aggregate may be made much more compact, while maintaining, or even increasing the capacity thereof. In the embodiment shown in Fig. 7 the blade system of the high pressure system is disposed immediately adjacent the casing of the low pressure system, but still it has been possible to provide space for a f sesame bearing located between the low pressure system 2 and the toothed wheel 4.

In the case herein described, a high pres-v sure turbine is understood to comprise a turbine working with a higher pressure than the low pressure turbine mounted on the shaft 5, and the exhaust steam of which constitutes admission steam, for another turbine.

' What I claim as new and desire to secure by Letters Patent of the United States of America is 1, A turbine aggregate, comprising a low pressure system, a sin 1e shaft carrying the low pressure system, a casing surrounding the low pressure system and provided with a steam supply portion, a high pres-:

pressure system, and a pinion. fixed on the shaft of the high pressure system and a' toothed gear fixed on the shaft of the low pressure system and adapted to be driven directly by said pinion. v

2. A turbine aggregate, comprising a low pressure system, a shaft carrying the low pressure system, a casing surrounding the -.low pressure system and provided w1th a cylindrical steam supply portion, a hi h pressure system, a casm surrounding t e high ressure system "and provided with a cylin rical exhaust steam portion, one of said portions being inserted in the other, a

resilient ring bet-ween said portions, a shaft carrying the high pressure system and journalled 1n the casing of the high pressure system, and a pinion fixed on the shaft of the high pressure system and a toothed gear fixed on the shaft ofthe low pressure system and'adapted to be driven b said -PiI1l0Il.

In testimonywhereof I a v x my signature.

FREDRIK LJUNGSTBGM.

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