US1095461A - Ship propulsion. - Google Patents

Description

W. L. R. EMMET.

SHIP PROPULSION.

APPLIOATIOI rILnn JULY 22,1909.

Patented May 5, 1914.

6 SHEETS-SHEET 1.

zki

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Witnesses W. L. R. BMME TF SHIP PROPULSION. urrlxoumn nun JULY 22,1909.

Patented May 5, 1914.

5 BHEETS-BHEET 2- o 1 ID IV I a: i N i e0 5 1 LL g: E i 7 I {B 8 {37, $8 i i D 4 IO I g I L 9 m Witnesses: Inventor:

I Y WiHiarnLR. mmet,

; I I b5 v W. L. R. EMMET.

SHIP PROPULSION.

nrmoulon nun JULY 22, 1909.

1,095,46 1 Patented May 5, 1914,

5 SHEETS-SHEET 3.

M E n' h F m n N 9 r- L) h- \o J R J Inventor: wltmessesz g WilliamLREImmet,

f 2% 7 I I JHLL W. L. R. EMMET.

SHIP PROPULSION.

nruoumn rum) 1112231909.

1,095,461 Patented May 5, 19M

5 BHEETSSHEET 4.

HP-Turbime l3 ml d I 1 F2) 1L 1 LL To Condens r,

m. a3 .E .0 'l- 0 9 a: c s g Witnesses: Inventor":

, WiI Iiam ljffm met,

w. L. R. EMMET.

SHIP PROPULSION. APPLICATION FILED JULY 22,1909.

Patented May 5, 1914.

5 BHEETS-SHEET 5.

m4 MW rmwm lnventor' WiH'iam L.R.Emmet, 5 Mfimj Witnesses 4 Maw TATES OFFICE,

n. mmn'n or sonnnnc'r'anr, NEW was; ASSIGN'OB .TO

ELECTRIC COMPANY, 11 conroan'rron or YORK.

SHIP rnorunsrox.

Specification of Letter: latent.

I am

' Patented Ma 5, 1914..

App ication filed my 22, 1900. Serial a... 508,942.

To all whom it may concern:

.- Be it known that 1, WILLIAM L. R. EM

1 awr', a citizen of the United States, residing at Schenectady,v county of Schenectady, State ofNew York, have .invented certam new and useful Improvements in Ship Propulsion, of which-the following is a specification. r 1

My invention relates to the propulsion of ships and has for its object to provide such an arrangement of propelling or motive v employed, but in certain cases onefshaftmay' be employedyand in other cases more thantwo. ,Mounted on each of these shafts is anelectric motor and also a low-pressure, low-speed turbine, the latter bein used as a general thing for high speed on y of the "sh1p. At cruisingspeeds the turbine will run idle in a vacuum or be disconnected.

Between the rotor of the turbine and that of the motor a coupling is or may/beinter posed so that the turbine can be disconnected rom the propeller-shaft. The turbines are arranged to exhaust into a suitable condenser. I'may condense all the steam in one condenser, or I may provide two or more condensers depending upon the distribution of theapparatus in the ship, and in using the term condenser I-aim to includesuch arrangements.

Atsome suitable place in the ship one,

bines are located, in the presentfembodiment two are shown, c nch oi WlllCh dr ves an electric generatorz, These eneratorsare connected to suitable con uctors or bus-bars and the latter supply current to the electric motors on the propeller shafts f ilForvone conditionof operation, 71. 6., cruising'speed of the ship, the high-pressure turbines arearranged to exhaust into the same condenser that is used with the low-pressureturbines, and toexhau st into the low-pressure turbines'and thence to "the condenser for another conditlon of operation, e., IINTIIIIHIH seed of the ship,

For cruising conditions t e high-pressura'high-speed turbines will alone extract the energy from the steam, but for high speed conditions they will extract only a portion, ed by When the ship is driven at cruisin speed, the propeller. shafts are driven soel by electric power through the agency 0 the generators, motors and their connectin conuctors, switches, etc. When-the s 'p is driven at maximum or full speed-condition,

the remainder being extractthe low-pressure, low-speed turbines.-

the driving is accomplishedby means of the high and low pressure turbines, electric generators, electric. motors and their connecting conductors, switches, et

Each of the high-pressureturbines is designed to operate at a high speed and one that is materially greater than is suitable for directly driving propeller shafts. This is attaine by dividing the turbine into stages, properly proportloning the nozzles to convey the steam at the desired pressureand velocity and giving the buckets a shape and speed to extract said velocity as fully as practicable, By operating these turbines at high speed the can be made comparatively light and simp .e for their output, as can also the-generators which are connected thereto. At full speed the highpressure turbines may for exampledeliver a little over' a fourth oft-he total ower, the remainder be- I prefer to use multi-stage impulse turbines and particularly those of the Curtis 'ing furnished by. t e low-pressure turbines.

type, since they possess many advantages in the way of high economy, simplicity of construction, and reduced shaft speed; My invention, however, is not necessarily limited to impulse turbines,- for I may employ reaction turbines,,for example, of the Parsons two 'or more high-speed, high-pressure tur- -.-.';ype, or I may use machines that are a 00mvbination ofthe impulse and reaction types. 5

'Th high-pressuxglturbines which I mp y high powers. To obtain this result each turbineis provided with, two outlets or exhaust pipes, one leading directly to the condenser and the other leading to the admission end.

.of a low pressure turbine. The'conduit leading directly to-the condenser is connected to-the turbine casingat a point beyond the last row of wheel buckets, The conduit leading to the low pressure turbine is, on the other hand, connected to the high-pressure turbine casing at a point corresponding with one of the intermediate stages or a region of intermediate pressure. The said pressure may be sixty or seventy pounds gage for example. In this conduit is an automatic valve that opens when the pressure in the particular stage or region of the turbine to which it is connected exceeds a predetermined value and permits the steam to discharge into the low-pressure turbine instead of into the condenser. By providing this conduit and locating a pressure responsive valve therein, the presence of an excessive or dangerous pressure in the high-pressure turbine is prevented and said turbine can pass automatically from condensing to non-condensing operation and vice versa. This valve also permits of the low-pressure turbine running in a vacuum when power is delivered by the high-pressure turbine only.

When operating as a condensing unit-, the turbine should have a sufiicient number of stages, each having the proper number of buckets operating at the necessary speed to.

extract the available energy fromqthe steam. When operating as a non-condensing unit, the turbine should have the proper number of stages and number of rows of buckets therein operating at the necessary speed to extract the available energy contained in the steam between its pressure of admission and that of the exhaust Whatever the latter may be. When the high-pressure turbine is of the impulse type, I prefer to provide it with a series of admission nozzles, some or all of which have suitable controlling valves operated by hand. At some point between the high-pressure and the low-pressure portions of the turbine, means are provided for cutting stages' into and out of service as by controlling the passage of steam through certain of the stage nozzles. This arrangement also enables me to control the distribution of pressures in the various stages. V 7 hen the turbine is operating as a condensing unit, some or all of these stage nozzles will be open and steam will "pass through all of the stages to thecondenser,

but when the machine is operating as a noncondensing unit, thesestage nozzles will be closed and the steam will pass at a compara-v tively high pressure from an intermediate stage to a low-pressure turbine. In other words, in the latter case, only a part of the stages of the high pressurmmachine are in operation, the remainder running idle in a vacuum due to the connection to the condenser.

For the purpose of reversing the ship or driving it backward, thehigh-pressure,

high-speed turbine may be provided with reversing buckets which are mounted on the same shaft whichcarries the forward driving buckets. Thesebuckets are arranged in stages of which one or more may be employed. The admission of steam to these buckets is controlled by a throttle valve, and, in addition, one or more nozzle valves may be, employed if desired.- Since the high-pressure, high-speed turbines are connected only to the generators and not to the propeller shafts, it follows that the reversing and backing of the ship in this instance are accomplished solely through the intermediary of the generator or generators and the electric motors. By reason of this arrangement the ship can be reversed by shutting off the main steam admission and admitting the steam to the reversing element. The electric generator and the motor are so organized and constructed that they will operate in synchronism. -This means that as the speed of the generator decreases to zero as the steam supply is cutoff, the speed of the motor will correspondingly decrease.

The admission of steam to thcreversing element then starts the generator into operation in the bpposite direction, and with it the rotor of the motor also-in said direction. Since the rot-or of the motor is direct-connected to the propeller shaft it follows that the direction of rotation of the shaft will also begreversed.

I so design and construct the low-pressureturbine or turbines that it or they can operate at a shaft speed which is adapted for directly driving propellers, whichspeed ismaterially below that at which the high I 1C pressure turblnes can be effectively operated. I so arrange the rotor of the low pressure turbine or turbines that it will counterbalance the thrust of the propeller in large part. Such an arrangement will relieve the thrust-bearing, and hence a simpler design of thrust bearing may be utilized.

' I prefer to employ alternating current, multi-phase generators of the synchronous type since these are well a daptedfor the purpose intended and can be driven at high speed, which speed is. best adapted with high-pressure turbines *for eiie'ctively extracting energy from the steam. By using high speed generators, they can be made relatively light and the size will be moderate for the output. I prefer to employ induction motors for the propeller shafts, each motor having a simple rotor of the squirrelcage type. Such amotor will operate with high efficiency. This motor will, be wound with a greater number of poles than the generator, so that it will always rotate at v a speed less than that of the generator. In

addition-tothis, a pole changing means is provided for changing the number of poles of the motor when it is desired to change the natural speed relation between it and the generator. For example, the generatorl.

may haveftwo poles and the motor four simplicity and effectiveness.

,5, connect the windings that the motor will have eight poles, and the speed. of its rotor i will be correspondingly reduced with respect to the generator. By avoiding all circuit changing devices for the motor ex- 11 9 cept the pole changers, the wiring of the system is a model of simplicity, and troubles incident to faulty operation of the electrical apparatus are reduced to a minimum.

Instead of reversing the ship by reversing the direction of rotation of the gener ator, and through it the motor, I may, under certain conditions, dispense with the reversing element on the high pressure turbine, and reverse the motors by means of 2@ suitable reversing switches placed in their circuits. In this event .the generator tur bine-or turbines will always run in the same direction. a

When a ship is operating at cruising speed, the power required is usually many times less than that required at the maximum speed and therefore, it Wlll generally be desirable, when operating at cruising speed, to use only one turb0generator unit. 33 to drive the motors, whereas it will be desirable to use two or more such units when the ship is operated at high speed. A highpressure turbo-generator can readily be cut into and out of service by the throttle valve as in the supply pipe and the switch connecting it to the bus-bars.

In order to control the speed of the ship whatever be the operating conditions,I vary the speed of the turbine driving the gener- 49 ator andthus maintain a state near synchronism of the electric generator and motor under all conditions of operation. This is one of the important features of my invention, since maintenance of such a condition affords maximum simplicity combined with highest efliciency. The electric apparatus used can be of low voltage with the simplest and most direct:

This affords a bond of ideal Moreover the use of low voltages reduces the danger to life and propertyand also the necessary amount of insulation, the latter having a direct bearing on the initial: cost and that of mainconnections.

tenance.

In case the ship is underway, and the low pressure turbine is disconnected from the propeller shaft, means may be provided by which a dangerous increased speed of the shaft of the low pressure turbine due 'to leakage7from a source of supply will cause .the main steam admission to be cut ofi. For this purpose I used an emergency stop valve in each main steam admission, and so 'ar- 56 ranged it that excessive speed of a low pressure turbine or turbines will cause it to close.

.Since the low pressure turbine wheels can be operated 1n a vacuum by reason of the casing being connected to the condenser, the losses incident to leaving the rotors of the low pressure turbines connected to the propeller shaft will be very small, and the maximum adaptability can be obtained by running in this way. If desired I can reverse the direction of the movementof the ship by installing a reversing element on the shaft ofthe low pressure turbine. If this is done, the low pres sure turbine can be used alone as a means'of propulsion whether in the forward or in the backward direction. Such a combination affords a meansof propulsion in case of emergency, and is also very desirable for maneuvering.

Other features of my invention will be set forth hereinafter.

Inthe accompanying drawings which illustrate one of the embodiments of my invention, Figure l is a top view, partially diagrammatic, of any improved apparatus arranged to propel a ship; F igi Zis a partial axial section of the highpressure, highspeed turbine; Fig. 8 is a partial axial section of the low-pressure, low-speed turbine; Fig. 4 is a detail viewshow-ing a reaction turbine adapted for use in my improved system; Fig. 5 is a detail'view showing the apparatus as applied to one of the propellers with the low-pressure turbine equipped with means for reversing it and also with a connection for admitting live steam; Fig. (3 is a diagrammatic View of,a separately excited turbine-driven generator; Fig. 7 is a detail view showing the means for cutting stage nozzles of a high pressureturbine into and out of service; and Fig. 8 is a diagrammatic detail view of an emergency stop valve controlled by speed governors driven by the shafts of the turbines.

Referring to Fig. 1, 10 and 11 indicate high-pressure, high-speed turbines. The former drivesthe three-phase alternating current generator 12, and the latter a similar generator 13. The rotors of each turbine and its generator aremounted on a shaft 14. Theshafts 14 are entirely inde- .pendent of the propeller shafts-and rotate at a speed largely in excess thereof. Steam is admitted to the turbines by pipes 15,

which are connected to the boilers. The exhaust of the turbines passes by the branched conduit 16 to the condenser 17, the auxiliaries being omitted to simplify the drawing. The conduit 16 is common to the forward driving and reversing elements of the highpressure turbines. At some intermediate. pressure point or stage the conduit 18 is connected to the casing of the high-pressure turbine l0 and extends to the low-pressure turbine 19. The high-pressure turbine 11 is provided with a similar conduit 20, discharging into the low-pressure turbine 21. The conduits 18 and 20 areprovided with automatic relief valves 22 and 23, each of which opens when the pressure in the predetermined stage or region in the high-pressure turbine exceeds a certain value, and discharges steam therefrom into its cooperating low-pressure turbine. W'hen the valves 22 and 23 are shut no steam is admitted to the low-pressure turbines and the chambers therein are at the pressure due to the condenser.

The low-pressure turbines are permanently connected to the condenser by the conduits 2 1. The rotor ofthe low-pressure turbine 19 is mounted on a shaft 25 which forms a continuation of the propeller shaft 26. Between the propeller shaft and the turbine shaft is a coupling 27 of suitable construction. Mounted on the propeller shaft is the rotor 28 of an induction motor, the field or stationary part 29 being mounted ona suitable support. On the end of the shaft 26 is a propeller 30 of suitable shape, size and pitch. The low-pressure turbine 21 is connected to the propeller shaft 35 by the coupling 36. Upon the propeller shaft is" mounted the rotor 87 of an induction motor, whose held, or. stationary element 38, is mounted on a suitable support. On the end of the propeller shaft 85 is 'a propeller 39 of the same character as the one previously described. The generators 12 and 13 are connected in multiple by the bus-bars -10, and switches 41 and 42 are provided by means of which the circuits of either or both the generators may be controlled. To the bus bars are connected conductors 13 which supply current to the motors. The motors are connected in multiple with respect to the bus bars and conductors. Each motor is provided with a pole'changing device let by means of which the number of poles in its field winding can be changed and the fixed speed relation between it and the generator changed.

In order to reverse the direction of movement of the ship, each of the high-pressure turbines is provided with a reversing element to be described more fully hereinafter. I can reverse by using one or more of the turbo-generators. Steam is admitted to the reversing element of one of the turbines by a conduit 45 having a suitable throttle valve 46.. Steam is admitted to the other turbine by a pipe 47 valve 48. Asv an additional means of governing the admission of steam to the reversing element, each turbine is provided with nozzle valves 49 that cut individual passages or nozzles into and out of service. Similar valves 50 are also provided for the high-pressure, forward driving portion of the turbines, whereby the speed of the turunder the control of a throttle.

bines can be varied by changing the number of nozzles in flow.

Under cruising speed conditions, the steam enters the high-pressure turbines and passes by the branched conduit 16 to the condenser. Under these conditions no steam will pass through the conduits l8 and 20. The current generated by the generators 12 and 13 is supplied to the induction motors which drive the propeller shafts. If the speed conditions are such that they donot require all of the power represented by the two turbines 10 and 11, I may cut one of these out of service and drive the ship solely by the other. The low speed turbines may remain coupled to the propeller shafts, or they may be uncoupled at the couplings 27 and 36. Owing to the fact that the rotors of the low-pressure turbines revolve in an attenuated atmosphere, the rotation losses will be very small and in many cases for this reason it will be found undesirable to disconnect the lowpressure turbines. Assuming that it is desired to drive the vessel at maximum speed, 4

steam is admitted to both of the high-pressure turbines and the ring or stage valves of both, to be hereinafter described, are moved in a direction to shut off their low-pressure portions. This results in building up the pressures in the stages to which the pipes 18 and 20 are connected to such a value as will cause the automatic relief valves 22 and 23 to open and discharge steam to the low-pressure turbines. Under these conditions all of the turbines and the generators and electric motors will participate in the propulsion of the vessel or ship. Since the lower pressure portion of each of the highpressure turbines is shut off, and since said portions are exposed to condenser pressure, the rotation losses of the idle bucket wheels will be very small.

leferring to Fig. 2, I have shown one of the high-pressure, high-speed turbines provided with a suitable casing 31 that ineloses the bucket wheels 51. The interior of the casing is divided into stages or wheel compartments by the diaphragms 52. In the present embodiment of my invention I have shown five stages each stage having two rows of wheel buckets and a row of intermediates that is more or less annular, depending upon the volume of steam to be handled. The first two stages are designed and constructed to effectively extract energy from high-pressure steam. The last three stages are designed and constructed to effectively extract energy from steam of lower pressure. 'Steam is admitted to the 'cates the high pressure steam chest; 57 the "which, in the turbine, and 58 the outlet connected to the branched pipe 16 and the condenser. 59 is the steam chest for the reversing element60, present embodiment of my in 'vention, comprises three rows of wheel buckets, and two rows of intermediate buckets. Steam is admitted to the buckets byv the sectional nozzle 61, each or'all of the sections of which are under the control of the nozzle valves 49. Since this turbine is designed to operate a part of the time as a condensing unit, and a part of the time as a non-condensing unit, a means must be provided fdr cutting out a certain number of stages. Such a means is found in-the ring valve ,62, to bemore fully described in connection with Fig. 7 At presentfit is suflicient to say that by turning this ring valve in one direction or the other the number ofv stage nozzles in service can be-varied from zero to a maximum.

When the high-pressure turbine is operating as acondensing unit, all five stagw are in service, the steam passing from the steam chest 56 through all the nozzles and buckets and escaping by the outlet 58 to the condenser. VVhen,-however, large power is de-v sired to propel the ship said turbine is operated non-condensing and the ring valve 62 is moved in a direction to close all the stage nozzles 63. Steam then enters by thes'team of the machine, and the pipe 18 chest 56, passes through the first two stages and passesby theoutlet 57 to the low-pressure turbine where it acts on the buckets therein and the'balance of the available energy is extracted after which it exhausts into the condenser.

Referring to Fig. 3, I have shown a lowpressure, low-speed turbine. This turbine comprises a casing 65 that is divided into stages or wheel compartments by the diaphragms 66. Located within the stages are rotatin elements 67 each of which carries rows 0 buckets with stationary intermediate buckets 68 between. In the first two stages there are three rows of buckets, each row being mounted on a disk, the ried by a hub 69 that is mounted on the shaft 25, Inthe last three stages, the wheel con struction difiers in that two disks 71 are employe'd which. support the ring 72 The moving buckets are secured to the rin 72 by any suitable means.- I have shown our rows of buckets mounted on the wheels of each of the last three stages,

stages if desired. As a--matter of fact,'I

prefer to employ more rows. of wheel buck-' ets, but owing to the small size of th'e drawpipe or conduit 18 or 20, as. the case may be, leading to a low pressure- ,drop in pressure in a or 20, as thecase may be,

disks being car-' tional area of the working passage is enbut I may em-. ployagreater. number in one or all of these may, however, be taken as ty fi'cal of any desired number of rows of hue ets. Steam is admitted to the first stage by a sectionalized nozzle 73, and to the subsequent stagesby sectionalizedstage nozzles 74, the cross-sectional area oi the nozzles increasing from the inlet toward the exhaust to accommodate the increased volume of steam. All of the buckets in all of the stages of this machine may act on the impulse principle, or some of them may act by impulse and others by impulse and reaction. I findit preferable to so arrange the rotor that it counterbalances wholly or in large part the thrust on the propeller shaft due to the 50 action of the propeller. This result is obtained by having the pressure on one side of at least one of the low-pressure drums greater than that on the other, the side of the drum having the higher pressure being away from the propeller, so that its un-- balanced thrust due to steam pressure is againstthat of the propeller. In carrying out this feature of my invention, the nozzle end-pressure is made greater than that at the point of discharge from the last row of buckets, and there is a corresponding step-by-step manner o ver'the face of the wheel as the steam flows across it. I may incorporate this idea in each of the stages of a low-pressure machine, or only in ap'ortien of them. 7 5 indicates 'the admission orifice of the turbine that is connected to the pipe=18 or 20 as the case may be. 76 indicates art annular chamber which supplies steam to the admission nozzlesl73. As a general proposition, the admission nozzles '73 will extend entirely or substantially around the turbine, so that all of the .wheel buckets will be active. The necessary increase in cross sectional area of the working passage beyond the initial stage may be obtained by increas .ing *the radial depth of the nozzles and buckets or by increasing the width oft-hepassages between the'buokets measured in a circumferential plane by changing the entrance and exit angles of the buckets, or b both methods, whichever is preferable." Theparticular manner in Which th6 cross seclarged is immaterial so long as the. passage i does enlarge and does not unduly restrict,-

or choke the freepassageof the fluid. Th

steam fromthe last stage enters the discharge opening 77 which itv is conveyed to'the condenser 17 by the conduit 24, iig. 1. a Referring to Fig. 4, I have shown my in vention in connection" with a reaction type of high-speed, high-pressuremachine, that 1 shown being of the well-known Parsons type modified ina manner to carry out my invention. For. light load or cruim'ng conditions, steam is 'admitted to the tur. 133

bine by the pipe 7 8 under the control of a throttle or other valve. The steam passes from the pipe 7 8 through the turbine acting on the successive rows of buckets until it is dlschargedby the conduit 7 9, which is connected to the pipe 16 leading to the condenser. For high or full-speed condition of operation, steam is admitted by the pipe 81 under the controlof a throttle valve to the turbine at a point where the cross-sectional area of the working passage is greater than at the point of admission by the pipe 78 and escapes by the outlet 82 and pipe 18 to the low pressure turbine. This pipe is provided with an automatic relief valve such as described in connection with Fig. 1. When the turbine is operating under heavy load conditions, the buckets in the low-.

"pressure end of the machine will be cut out 20 of service by valves or other means acting 2 Fig. 7. v

portion oftheqiower planton one "side of V 80' the center lineflt I the center line is a duplicate 10a? pressure Referringfto' Fig. 5, I have shown a modification of my invention with respect to a low-pressureturbine; This figure shows the rough the condenser. The plant on'the "opposite side of .that shown. and the two portions are connected in the manner indicated. It isarranged to be portion of :the

' 8t driven by steam exhausting. from the highpressure, high-speed turbine or by highpremuresteam directly. from the boiler, or by a combination of high-pressure and low-- 40 ship. In other words,'in this particular embodiment of my invention the low-pressure turbine is a mixed-flow or mixed-pressure turbine. Steam from the low-pressure source is admitted by the conduit 84 and from the high-pressure source by the conduit 85.. This latter conduit supplies steam through the throttle valve86 to the steam chest 87. The nozzles leading fromv the steam chest '87 have a greater expansion steam for forward driving of the ring valve 62 that has been previouslyreelement may be similar .to that described in connection with Fig. 2. Steam is admitted to the buckets and their supply nozzles from opened, it being understood, of course, that the high-pressure turbine must be stopped. The arrangement of the motoron the propeller shaft, etc., is ,the same as thatpreviously described, and the description need not 'be repeated. 1

In order -to operate the electrical apparatus with high efficiency under light load conditions, 2'. 6., cruising speed, it'is desirable to reduce the fixed lossestoa minimum by changing the magnetic density of the iron in the generator. To this end I employ a separate exciter 93 for each of the generators, or" one exciter may serve "for all the generators. In circuit with the armature of the exciter is a-resistance 94: which can be increased or decreased. as it. becomes neces sary'to vary thec rren't flowing in the-circuit to decrease 0' increase; the magnetic density ofthe iro in the generator; The exciter is controlled by varying the resistance 95 in its'field circuit. The xciter may be driven in any suitable manner, as, for

example, by a small turbine or otherengine.

Referring to Fig. 7 I have shown the ferred to in connection with Figs. 2 and 4 for cutting sections "of the stage nozzles 63 L means of-wh chthe ring valve 15' moved an- WTWhich b kets are r'eversely disposed with gularly above its axis. The valve is pro "vided with openings 99 and-blank walls between said opemngs. Y IVhen said openings are directly oppolsite the nozzles 63, shown in dotted lines, al the steam from the preceding stage or portion of the turbine will pass through said nozzles or passages, but

as the nozzle openings or passages are cut I off one by one. by moving the ring valve an- 7 gularly about its axis the eflective opendecreased. In the position shown,

50 ratiothan do the nozzles leading from the low pressure steam chest 88, the obiect ofthis to reduce the pressure of the steam to that of the stage pressure into which. it is discharged. Thevelocity of.

. b5 steam sodischarged willbe higher than that from the other nozzles but th1s will not interfere with theeconomy'of operation, since .& whatever-energy is not utilized in'the first stage will be substantially utilized in the 60 subsequent stages. In order to reverse the turbine and theship, reversing buckets are mounted on one'end of the turlpine'rotor,

mg is all "of the nozzles or passages are out of service. This is the relationof parts when the high-pressure turbine is operating noncondensing. Referring to Fig. 8, I-have shown; an au-: 180

respect to those on the other en The ar- 65'range1nent of the buckets of the reyersing' r tomatic stopvalve which is located in the main steam pipe admitting steam to the turbines. When more than a single pipe is employed for admittin high-pressure steam to 'the turbines, oneo these valves may be located in each of the pipes. The valve 100 105 This (governor comprises a ring that is so arrange that its periphery is normally concentric to the'axis of the-shaft, although its mass is not symmetrically arranged with respect to said axis, but as the speed increases abnormally, say 10 per cent, for ex ample, the ring moves laterally with respect to the shaft axis against the action of' a spring that tends to keep it concentric and engaging the lever 106 causes the member I 107 to bridge the contacts adjacent thereto and to close the circuit of the solenoid magnet 108. The core of this magnet when energized pulls the detent 103 out of the notch in the nut thereby ermitting the valve to close due to its -un alanced tendency, the

nut 102 sliding'down with it. .To reset the valve, the hand wheel is first rotated in the valve-closing direction which raises the nut to normal position, after. which the detent 103- is moved toitheposition shown, either automatically or by hand. After the nut is locked, the valve can be manipulated by the hand wheel ,the same as any other nut and screw valve; By using electric, mechanical or'fluid pressure means for transmitting the effects of the governor to the combined throttle and stopvalve, the valve may be made-res on'sive to the abnormal speed conditions 0 any one or all. of the turbines, it-

- being understood in the latter case that each i a conditionylas this'mi o turbine will haveqan emergency governor.

The manner of arranging"v a second emergencygovernor 109. to-en'ergize the solenoid" -108 is'illustra d in Fig.8. The valve" will shut down thelow-pressur'e turbine whether it is connected tothe-propell'er shaft or not,

provided its speedbecomes excessive. Such I i-assure turbin'e' was disconnected from the gprope'ller shaft and steam were to leak th'e'conduit 18 or 20.

.In 'dddi tionto the advant'ages heretofore forth myiinvention has the advantage of the initial cost and also the space occupiedsJyL-"the moti e powerapparatus; Byim'provln'g the'cono n'y" I reduce the nect' exist if the lowessary number of boilers orthe size of the boilers if the same number is retained, the

space occupied thereby, and the coal consumption. The space thus saved can be used for coal bunkers thereby increasing the cruising radius of the ship which is a factor of the greatest practical value.-. By careful calculation I find that I can about double the cruising radius of ships of certain designs. Owing to the character of the parts of. my improved system they can be arranged ,in the ship in a manner to obtain the best distribution of weight. I am also able to reduce the ,length of each of the propeller-shafts, thereby reducing not only the weight but the number of bearings employed.

I have employed the term steam to designate the motive fluid used to drive the turbines but it is to be understood that other vapors having the same general character-- 'istics as steam liberatedby boiling water maybe utilized.

I do not broadly claim the idea of reversing' a propeller shaft which is driven by ,an electric motor by reversing the direction of rotation of its generator and its prime mover since it is the im'ention of another, but limit myself to combinations in which this feature is an element.

The terms high-pressure and lowpressure as used in this case' are relative.

The former does not have reference to any particular pressure and neither does the lat- H ter. They simply mean that'oneis higher than the other. The region of intermediate pressure referred to may have any desired value. It may be'that of atmospheric pressure or it may be above or below that pressure. As a general thing will 'be found desirable to maintain this intermediate pressure at a value considerably above that of the atmosphere because with the arrangement described it results in a greater economy of operation for the different conditions of service than where a lower pressure is employed.

, I have described certain arrangements-of the turbines, generators and motors for obtaming'certaln speeds ofthe ship butjitis evident that other speeds ca'n bejpbtained by; proper modifications o'fthe steam and; elees' trical connections as will the foregoingdescription;

The feature of the emergency governing mechanism herein described be W-f m v 1,0 is not claimed 1 because it forms the subject matter of my applic ion Serial No. ber '18,. 1918. 1

In accordanoewith the provisions of the patent statutes, .1 have describedfthe principle of operation obmy inventio together i with the apparatus 'vvhich I now consider to represent the best embodiment thereof; but

I I desireto have it understood that the up bine orgamzedand constructed for conperet n, n ereby, ,a low- (lensing and non-condensin electric generator driven. 51 speed, low-p'ressure turbine driven by steam from the first afterit has passed through ,a portion only of saidturbine, a propeller and its shaft direct-connected to the rotor of the low-pressure turbine, and a'motor organized and constructed to rotatejat a lower speed than the generator and receiving current therefrom, thefrotor of the motor being a mounted on the propeller shaft.

'2. In a system of sh'p propulsion, the combination of a high-pressure, high-speed I turbine,-- an electric generator driven thereby, a low-speed, low-pressure turbine drlven by the'exhaust from the first turbine, a pro:

peller'and its shaft direct-connected to the rotorof the low-pressure turbine,- a motor organized and constructed to rotate at a lower speed than the generator and receivingcurrent therefrom, the rotor of the mo tor being mounted on the propeller "shaft, and a pole-changing means for changing the natural speed-relation between the rotor of th e high to the low-pressure turbine,

the motor and that of the generator.

3. In a system of ship propulsion, thecombination of a.high-speed, high-pressure turbine organized and constructed to operate as acondensing unit forlow speeds of the ship and-asa non-condensing. unit for higher speeds of the ship, a low-pressure,

low-speed turbine arranged to receive the exhaust from the high pressure turbinewhenthelatter is operating non-condensing,- the rotor of the low-pressure turbine'being adapted to be connected to the propeller shaft, acondensinglmeans for the low-pres,-

sure turbine, a connection extending from' the high-pressure turbine tothe condensing means, a second connection extending from a propellerl shaft, a generator driven by the hi ghpressure turbine, and a motor on sald shaft and driven by current from the generator. 4

, ice andbothturbines,

4, I a system of ship propulsion, the

combination of-a-- main high-pressure tur bine, a low-pressure turbine, the latter being driven by the exhaust from the former; an electric generator driven bythe mam turbine, a propeller; and its shaft, an electric motor onsaid shaftwhichis driven by current fromthe generator, means for causing the main turbine, generator and motor to drive the --pi'opeller for generator-and motor tod'rive it for other conditions of serv ce, and means for cutting. a portion of the highone condition of serv pressure turbine out of service when the low-pressure turbine is receiving steam and is assisting in propelling the ship.

5. In a system of ship propulsion, the combination of high-pressure and low-pressure turbines, a conduit conveying the exhaust of the former to the latter, an automat-ic valve in the conduit responsive to pressure, an electric generator driven by the high-pressure turbine, a propeller and its shaft,an electric motor onv said shaft which is driven by current from the generator,

generator and motor to drive the propeller for one condition of service and both tur-. bines, generator and motor to drive it for other conditions of service, and means for reversing the. direction of rotation of the propeller and its'shaft'.

6. In a system of ship propulsion, the combination of a plurality of propellers and their shafts, high-pressure, high-speed turbines', electric generators driven thereby, low-speed, low-pressure turbines, one on each ofsaid shaft-s which are adapted to receive the exhaust from the high-pressure turbines andbe driven thereby, condensing means, electric' motors mounted on the propeller shafts, conductors connecting the m0- tors and generators, and switches arranged to connect the motors in circuit with one or more of the generators.

bination of a plurality of propellers and their electric generators driven thereby, low-speed, lowpress'ure turbines one on each of said shafts which are'adapted'to receive exhaust driven thereby, electric motors mounted on the propeller shafts, conductors connecting ranged-t0 connect the motors in circuit with one or more of the generators, and meansfor'changing the natural speed relation between the rotors of the generators and motors.

8. In a system of ship propulsion, the combination of main turbines, each divided into high and low-pressure portions, lowpressure turbines, propellers and shafts main turbines, electric motors on said shafts,

generatorsand motors to drive the shafts solely'by electrical means at cruising speeds,

pressure portion of each main turbine with ajlow-prcssure turbine, the two being 'ar ranged in series as to steam, means for causing the generators and motorsto cooperate mWI lth the low-pressure turbines to drive the means for causing the high-pressure turbine,-

' 7 In a system of ship, Dropuisiomthe comshafts, high-pressure, high-speed turbines,

from the high-pressure turbines and. be

the motors and generators, switches are condensing means, means connecting the therefor, electric generators driven by the means connecting the exhaust of the highshafts at higher speeds of the ship, and f means-for reversingthe direction of-'rota--. tion of the propellers and theirshafts. p

' turbine, a low-speed, low-pressure turbine,

- 9. In a system of ship propulsion, the combination of a high-pressure, high-speed a condenser, a conduit leading from a region of intermediate pressure in the highpressure turbine to the low-pressure turbine, valve means for controlling the flow of steam in the highressure turbine beyond said region, con uits connecting the exhaust openings of both turbines with the condenser, an electric generator driven by the high-pressure turbine, a propeller and its shaft, the latter being connected to the rotor'of the low pressure turbine, an electric motor on the shaft which is connected electrically to the generator, and means controlling the admission of steam to the highpressure turbine.

10. In a system of ship propulsion, the combination of a high-pressure turbine that is organized and constructed to operate as a condensing unit for lower speeds of the ship and as a non-condensing unit for higher speeds, a condenser connected to the outlet of the turbine, a low-pressure turbine that exhausts into the condenser, a conduit connected to a region of intermediate pressure in the high-pressure turbine and to the inlet of the low-pressure turbine, a valve in said conduit that is responsive to pressure changes, a propeller and its shaft,

means for delivering the power developed by the turbines to the shaft, and a valve mechanism for controlling the admission of steam to the high-pressure turbine.

11. In a system of ship propulsion, the combination of a high-pressure turbine that is organized and constructed to operate as a condensing unit for lower speeds of the ship and as a non-condensing unit for higher speeds, a condenser connected to the outlet of the turbine, a low-pressure turbine that exhausts into the condenser, a conduit connected to a region of intermediate pressure in the high-pressure turbine and to the inlet of the low-pressure turbine, valve mechanism in the high-pressure turbine for shutting oif its low-pressureportion when operatin non-condensing, an automatic valve in said conduit which opens and discharges steam to the low-pressure turbine when the pressure in saidregion reaches a certain value, a propeller and its shaft, means for delivering the power de- Veloped by the turbines to-the propeller, and a regulator for the high-pressure tur- 12. In a system of ship propulsion, the combination of high and'loW-pressure turbines, the former operating at a higher speed than the latter, an electric generator driven by the high-pressure turbine, a propeller and its shaft drivjenby the low-pressure turbine, 'anel'e ctric motor which receives energy from the generator and Who e r t r is mounted on said shaft, condensing means, means for operating the h gh-pressure turbine as a condensing or as a non-condensing unlt, means for controlling the admisslon of steam to the'high-pressure turbine and thereforeits speed, and means for varying the field excitation of the generator.

the high and low-pressure turbines Qperat- 35' ing with dissimilar speeds, condensing means receiving steam from the second named condu t and the low-pressure turbine, a regulator for the high-pressure turbine, a propelle'r and its shaft, said shaft being adapted to be direct-driven by the low-pressure turbine, and a speed reducing connection for transmitting the power developed. by the high-pressure turbine to the propeller and its shaft. r g 14. In a system of ship propulsion, the

combination of a high-speed, high-pressure engine, an electriegenerator driven thereby,. w

a low-pressure, low-speed turbine, a propeller and its shaft direct-connected to the turbine, an electric motormounted on the propeller shaft and constructedtand organized to operate at a lower speed than the generator, conductors connecting the generator and motor, condensing means, conduit 1 5 means discharging the exhaust steam from the engine direct tothe condenser for ,con-

'ditions of low speeds of the ship, conduitmeans automatically discharging steam from the engine to the turbine for higher speeds after it has given up some of its/energy 1n the engine and a regulator for controlling the speed of the ship both for low and high speeds which varies the admission of steam c to "the engine.

15. In a system of ship propulsion, thecombination of a; high-pressure, high-speed engine, a generator driven thereby, a lowpressure, low-speed turbine that is driven by the exhaust from the engine, a propeller andits shaft which are direct-connected to the turbine, a motor on the propeller shaft that receives current from the generator and" is driven thereby, and a means for supplying live steam to the turbine to supplement its 12:;

supply of exhaust steam and to drive the turbine when. the ngine s 1dle.

16. In a system of ship propulsion, the

combination of a turbine constructed and arranged to operate condensing and non- 1m 'condensiiig, an electric ,generator driven thereby, a low-pressure, low-speed turbine that isnormally driven by the exhaust from the first, condensingv means for the turbines, a propeller and its shaft connected to the rotor of the low-pressure turbine, an electric motor on the propeller shaft Which'receiyes current from the generator, reversing buckets mountedon the low-pressure turbine rotor,

meam for admitting live steam to the reversing element when it is desired to reverse the ship, and means controlling the admission of steam to the turbine that drives the generator, Y

17. In a system of ship propulsion,-the combination of a turbine constructed and arranged to operate condensing and noncondensing, an electric generator driven thereby, a low-pressure, low-speed turbine that is normally driven by the exhaust from the first, condensing means for the turbines, a propeller and its shaft connected, to the rotor of the low-pressure turbine, an electric motor on the propeller shaft which receives current. from the generator, reversing buckets mounted on the low-pressure turbine ro.tor,.means for admitting live steam to the reversing element fwhen it'is desired to reverse the ship, means controlling the admis sion of steam to-the turbine that drives the generator, and means for admitting live steam'to low-pressure turbine. 1

'18. In a system of ship propulsion, the combination of a turbine constructed and arranged cooperate condensing and noncondensing, means for cutting a portion of the "turbine buckets out of service for noncondensing operation, an electric generator driven by the turbine, apropeller and its 40 shaft, an electric motor mounted on the shaft which receives its current from the generator, the generator and motordriving the ship at certain speeds, a low-pressure turbine whose rotor is connected to the ropeller shaft, means for admitting steam rrom the generator-turbine to the low-pressure turbine when it is desired to propelthe ship at higher speeds, condensing means for the turbines, .and means for cutting the electrical apparatus out of service and admitting steam to the low-pressure turbine when it is desired. to maneuver the ship.

19: In a system Ofship propulsion,the combination of a high-pressure turbine, an alternating-current generator driven thereby, a low-pressure turbine, condensing means, conduit means for discharging steam from the high-pressure turbine to the condenser for operating it condensing and to thelow-pr'essure turbine for operating it non-condensing, a propeller and its shaft which are driven by the low-pressure turbine when itis receiving steam, an induction motor having its armature mounted on said shaft, the field winding of said motor receiving current from the generator, and means for changing the connections of the field winding oi} the motor to change the number of its poles. i

20. In a system of ship propulsion, the

combination of a high-pressure turbine having a'bucket-carrying element, a generator driven thereby, a low-pressure multistage turbine receiving motive fluid from said high-pressure turbine and havinga bucket 7 5,

carrying element that exerts an axial thrust which opposes that of the propeller, a propeller and shaft connected to said element, the bucket-carrying elements of the turbines rotating at dilierent speecsga motor the propeller shaft receiving current from said generator, condenser means, means for operating the higlnpressure turbine as a condensing or as a non-condensing unit, and means for controlling the admission of steam to the high-pressure turbine.

- In witness whereof, I have hereunto set my hand this 20th day of Jul; 1909.

i WELLEAM lb. R, MMET. Witnesses: BENJAMINJB. Hunt, Human @Rronn

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