US1118885A - Elastic-fluid turbine. - Google Patents

Description

K. ALQUIST.. ELASTIG FLUID TURBINE. APPLICATION FILED APR.16. 1914.

1,118,885, Patented N0v.24,1914.

2 SHEETS-SHEET l.

I nven'or Kar-l .9CH l35,

K. ALQUIST.

BLASTIG FLUID TURBINE.

APPLICATION FILED APR.16.191-4. 1,1 18,885, Patented Nov. 94, 1914V Z SHEETS -SHEE'I 2.

Kar-L uis-t,

Hisaft 'rne5.

v'number -of bucket rings are re ulred KARL amursr, or scnnnncranr, New Yoan.

i Emeric-FLUID TURBINE.

Specication of Letters Patent.

Patented Nov. 24, 1914.

Application led April 16, 1914. Serial No. 832,228.

turbines, for marine propulsion bui t up of' forward and reversing elements as isA well known. i

In connection with the design of steam turbines, particularly multi-stage turbines of the impulse type, a comparatively large m order to obtain a high eiliciency. T is makes the distance between bearing centers large which necessitates a large shaft diameter. The large shaft diameter has further to be 'carried all through the length of the turbine in order to obviate the end thrust which would be caused by shaft'packings of different diameters, though otherwise, so far as stiffness is concerned, the shaft might be made to taper ofi' toward the ends thereby saving in both material and weight. The lar e shaft diameter requires the use of pac 'ngs of greater diameter which means greater loss due to steam leakage. Further the packing clearances have generally t0 be increased as the surface speed of the shaft increases, so that the losses go up in. a higher ratio than the shaft diameter. In a reversing turbine .the diiiiculties described are more pronounced because of the extra bucket rings which have to be added for reversing purposes and which further increase the length of the shaft. A solution sometimes employed for overcoming the above difliculties which consists in runnin the turbines above the critical speed 1s not available for marine turbines, as a turbine -should run through the critical speed as the forward elements into two groups, a

'high pressure group and a low pressure group, placed one on each side of the reversing elements which thus occupy the middle portion in the turbine. I may use only two bearings for the unit, or I\ may provide also one intermediate bearing placed preferably between the reversing elements and the low pressure group of the forward elements. The motive fluid for forward operation is led first to the high .pressure group of forward elements and then by a suitable conduit across to the low pressure group. The flow through the forward low pressure group is 'in a reverse direction to that through the reversing elementsf This enables me to use a common exhaust chamber thereby saving materially in the length of the turbine and consequently in 'the shaft diameter. By this arrangement I am also enabled to use a shaft having its largest diameter at the middle and ste pcd to a smaller diameter at the ends, and still halance the end thrust, as will be more fully explained hereinafter.

Referring to the drawings wherein have partly in section o a turbine embodying the features of my invention; Fig. 2 is an end view partly in sectionl looking toward the right of Fig. 1, the part in section being ta :en on line 2 2 of Fig. 1; Fig. 3 is a view similar to Fig. 1 of a modified form, and Fig. 4 is a section taken on 1ine -1-4, Fig. 3.

-Referring first to Fig. 1, 5 is the turbine shaft carrying the two groups of forward elements 6 and 7, and the group of reversing elements 8, th latter being arranged between the groupeof elements 6 and 7. As shown, the group 6 is the high pressure scction and the group 7 is-the low pressure section. 9 and 10 are suitable hearings for the shaft, and at 11 and -12 are -shown the shell shaft packings. 13 is the .common exhaust chamber.

The motive Huid, as steam-,uis fed to the high pressure forward wheel or wheels by passages 14, and to the reversing wheel c; wheels by passages 15. These passages are preferably arranged in the same -plane and are separated from each other by the wall or artition 16. Motive iiuid is led to the tur ine by the conduit I17 which is branched` wams/Sel at the low pressure s ages, the leakage losses l as indicated at 1s and '19, the branch 1e leadlng to 'passages 1 4 and the branch 19 to passages 15. The passage of motive fluid through the conduit 17 is controlledfbyithe ing'it`s"frward elements divided into two arranged one on each side of the 70 -r'eversmg elements. 4-

the passage of fluid to the forward or revalve 20, which may be of any preferred form, hand controlled or otherwise, while versing elements is controlled by the valve mechanisxnQl, which is arranged so that it may be adjusted to direct the steam t0 eitherl branch 18 or 19. In the case of forward operation the motive fluid first asses through the group 6, then by way ofp conduit 22 to group 7, and throughk grou'p 7 to the chamber 13, and out through the exhaust o ening. In reverse'operation the motive uid passes l,directly through the elements Q to .the exhaust chamber. It will be noted that the shaft 5 is ofgreatest diameter at the point midway between `the bearing centers and that it is stepped vdown to a' smaller diameter at the bearm. The shell packings 1`I"and 12 at are thus small in diameter- -and the the en end thrust is balanced as there is about the 'same steam pressure at the two ends.4 If

found necessary the'shaftvdiametrs may be' adjusted so -as to obtain the desired pres# sure balance. ,It will also be apparent that as the large packin `diameters only occur willbe smalh The arrangementshgwn' in Figsf and v4 is substantially the same as thatshwn in Figs. 1and2 except that in these es' an intermediate bearing is provide as shown at'` 24,a'nd the turbine is shown as exhausting inten'l condenser 25 arranged 'below'the same instead of through an open,- 'ing at the top, as in Fig. l, The same reference numerals have accordingly been applied tothe corresponding parts in Figs. 3i

and 4 as are used 1n connection with Figs. 1 and 2. When an intermediate bearin is. used', the rotors may conveniently be divi ed up'ninto two groups of about equal size, one

on each side of the intermediate bearing,- and the exhaust passages 26 and 27 will then partly surround this bearing and conneet the rotor housings so as to m'ake them form one rigid structure. In the arrangement as shown in Figs. 3 and 4f,l the shaft isreduced in size at the intermediate bearing," the'shaft being greatest in diameter at the"points" midway between the intermediate bearing and the end bearings.`

In accordancewith the provisions `of the patent statutes,'Ihave 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 ap aratus shown is Ionly illustrative and t at the invention can' be carried out by other means.

groups between the two 1` 'ing its forward elements divided into a high pressure group and a low pressure group arranged one on each side of the reversing section, the final stages of the low pressure group and of the reversing section being arranged to face'each other and'exf haust into a common chamber.

3. A reversible elastic Huid turbine having its forward elements divided into a. high pressure group and a low` pr 'ure group arranged one on each side o the reversing section, a conduit Vforconveying motive fluid to the forward and reversing sections, and acommon' controlling valveI mechanismfor directing the motive .Huid to either of said sections. E 4., In an .elastic fluid turbine, thecombination of a shaft, bearinl therefor, said shaft having its Agreatest ameter midway between the bearings and stepped down to a smaller diameter at the b'armgs, forward.

a reversing section carriegll aft1 which is located. between e 'forwardt groups;-.. f.

In an elasticluid turbine,the combnation of-a shaft, a forward' section carried 1100 thereb which is divided intotwo groups' space apart, eqreversing section arranged rups, and' and an intermedia bearing for id sha t.

6..In an elastic 'fluid tur ine, the combi-'105 nation of a shaft, a forward section carried therebyvwhich is divided into two groups spaced apart, a reversing section arranged between the two groups,the final sta es of the forward and reversing sections acing 11o each other and exhausting into a ,common chamber, and end bearings and an intermediate bearin forysaid' shaft.

7. In an e astio Huid turbine, the combi-4 nation of a shaft, forward elements divided into a high pressure group and a low pressure group carried by the shaft and spaced` apart, a reversing section between the two groups,`the final stages of the low pressure group and the reversing section facing each Ito group and the reversng section facing each other, end bearings for the shaftfnn intermediate bearing therefor located between the 16WA pressure group and the reversing -5 'section, `a housing for the elements on the op osteides of the intermediate' bearing,

an an exhaust chamber, the walls of which partly surround Athe intermediate bearing

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